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Physics Questions

Find the height

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If a man weighs 90 N on the surface of the Earth, then the height above the surface of the earth of radius R, when the height is where the weight is 30N is

A.0.73R

B. R/√3

C.3R

D.√3R

Anonymous User tag : Physics 11 Nov, 2019 1 Answer 74 views

A block of mass 2 kg is attached to one end of a massless rod of length 1/22/7 m . The rod is fixed to a horizontal plane at the other end such that the block and rod are free to revolve on a horizontal plane. The coefficient of friction between the block and surface is 0.1. Block is made to rotate with uniform speed by applying a constant external force in tangential direction on the block. The work done by external force when the rod rotates by 90 degreeis

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A block of mass 2 kg is attached to one end of a massless rod of length  . The rod is fixed to a horizontal plane at the other end such that the block and rod are free to revolve on a horizontal plane. The coefficient of friction between the block and surface is 0.1. Block is made to rotate with uniform speed by applying a constant external force in tangential direction on the block. The work is done by external force when the rod rotates by 90 degree is

Anonymous User tag : Physics 25 Oct, 2019 1 Answer 100 views

In a hypothetical concept, electron of mass me revolveds around nucleus due to gravitational force of attraction between electron and proton of mass mp. If the radius of circular path of electron is r then the speed of electron is ?

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In a hypothetical concept, electron of mass me revolveds around nucleus due to gravitational force of attraction between electron and proton of mass mp. If the radius of circular path of electron is r then the speed of electron is ?

Anonymous User tag : Physics 15 Oct, 2019 0 Answer 66 views

Two identical discs of mass m and of radius R touch each other and move with the same velocity perpendicularly to the line segment which joins their centres of mass, along the surface of a horizontal smooth tabletop. There is a third disc of mass M and of radius R at rest, at a point on the perpendicular bisector of the line segment joining the centres of mass of the two moving discs as shown in the figure. The two moving discs collide elastically with the third one, which is at rest. There is no friction between the rims of the discs. What should the ratio of M/m be in order that after the collision the two discs of mass m move perpendicularly to their initial velocity?

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Two identical discs of mass m and of radius R touch each other and move with the same velocity perpendicularly to the line segment which joins their centres of mass, along the surface of a horizontal smooth tabletop. There is a third disc of mass M and of radius R at rest, at a point on the perpendicular bisector of the line segment joining the centres of mass of the two moving discs as shown in the figure. The two moving discs collide elastically with the third one, which is at rest. There is no friction between the rims of the discs. What should the ratio of M/m be in order that after the collision the two discs of mass m move perpendicularly to their initial velocity?

 

Anonymous User tag : Physics 09 Oct, 2019 1 Answer 63 views

current

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A WIRE HAS LINEAR RESISTANCE P. FIND RESISTANCE R B/W PoinT A AND B IF SIDE OF LARGER SQUARE IS D

Anonymous User tag : Physics 06 Oct, 2019 0 Answer 62 views

CURRENT

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A WIRE HAS LINEAR RESISTANCE P FIND RESISTANCE R B/W PT A AND B IF SIDE OF LARGER SQUARE IS D

A AND B ARE OPP POINTS ON LARGER SQUARE

Anonymous User tag : Physics 06 Oct, 2019 0 Answer 68 views

ELECRTOSTATICS

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10 uc charge is uniformly distributed over thin ring of radius 1m a particle of mass 0.9 g charge 1uc is placed on axis of ring it is displaced towards centre then time period is

Anonymous User tag : Physics 02 Oct, 2019 1 Answer 74 views

thermo

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1 cm3 of water at its bp absorbs 540 cal of heat to become stream with vol of 1671 cm3 if atmpressur1.013 *10^5 n/m2 and mechanical equivalent of heat =4.19 j/cal energy spent in this process in over coming intermolecular forces

Anonymous User tag : Physics 01 Oct, 2019 1 Answer 74 views

a stationary obj at 4 deg cal and weighing 3.5kg falls from height of 2000 m on snow mountain at 0 degc if temp of obj just hitting snow is 0 deg and obj comes to rest immediately obj melt at (latent heat of ice=3.5*10^5 j/s)

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a stationary obj at 4 deg cal and weighing 3.5kg falls from height of 2000 m on snow mountain at 0 degc if temp of obj just hitting snow is 0 deg and obj comes to rest immediately obj melt at (latent heat of ice=3.5*10^5 j/s)

Anonymous User tag : Physics 20 Sep, 2019 1 Answer 80 views

A block of mass m is placed on an another rough block of mass M and both are moving horizontally with same acceleration a due to a force which is applied on the lower block, then work done by lower block on the upper block in moving a distance s will be?

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A block of mass m is placed on an another rough block of mass M and both are moving horizontally with same acceleration a due to a force which is applied on the lower block, then work done by lower block on the upper block in moving a distance s will be?

Anonymous User tag : Physics 15 Sep, 2019 1 Answer 60 views

A particle is projected with a speed u in air at angle θ with the horizontal. The particle explodes at the highest point of its path into two equal fragments, one of the fragments moving up straight with a speed u. The difference in time in which the two particle fall on the ground is (Assume it is at a height H at the time of explosion)

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A particle is projected with a speed u in air at angle θ with the horizontal. The particle explodes at the highest point of its path into two equal fragments, one of the fragments moving up straight with a speed u. The difference in time in which the two particle fall on the ground is (Assume it is at a height H at the time of explosion)

Anonymous User tag : Physics 12 Sep, 2019 0 Answer 57 views

Two particles of mass M = 3 kg each are kept on a horizontal circular platform on two mutually perpendicular radii at equal distance R = 1 m from the centre of the table. The particles are connected with a string, which is just taught when the platform is not rotating. Coefficient of friction between the platform and block is  = 0.1. Then the maximum angular speed ( in rad/sec) of platform about its centre so that the blocks remain stationary relative to platform. (take g = 10 m/s2)

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Two particles of mass M = 3 kg each are kept on a horizontal circular platform on two mutually perpendicular radii at equal distance R = 1 m from the centre of the table. The particles are connected with a string, which is just taught when the platform is not rotating. Coefficient of friction between the platform and block is  = 0.1. Then the maximum angular speed ( in rad/sec) of platform about its centre so that the blocks remain stationary relative to platform. (take g = 10 m/s2)

Anonymous User tag : Physics 09 Sep, 2019 0 Answer 59 views

A spring is compressed between two blocks of masses m1 and m2 placed on a horizontal frictionless surface. When the blocks are released. The blocks travel distance x1 and x2 respectively before coming to rest. The ratio x1/x2 is?

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A spring is compressed between two blocks of masses m1 and m2 placed on a horizontal frictionless surface. When the blocks are released. The blocks travel distance x1 and x2 respectively before coming to rest. The ratio x1/x2 is?

Anonymous User tag : Physics 09 Sep, 2019 1 Answer 64 views

A uniform solid hemisphere of radius 10 m and mass 64 kg is placed with its curved surface on the smooth horizontal surface and a string AB of length 4m is attached to point A on its rim as shown in the figure. Find the tension in the string if hemisphere is in equilibrium.

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A uniform solid hemisphere of radius 10 m and mass 64 kg is placed with its curved surface on the smooth horizontal surface and a string AB of length 4m is attached to point A on its rim as shown in the figure. Find the tension in the string if hemisphere is in equilibrium.

Anonymous User tag : Physics 15 Aug, 2019 1 Answer 90 views

A uniform rod of mass M and length L is free to rotate about a frictionless pivot located L/3 from one end. The rod is released from rest incrementally away from being perfectly vertical, resulting in the rod rotating clockwise about the pivot. When the rod is horizontal, what is the magnitude of the tangential acceleration of its center of mass?

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A uniform rod of mass M and length L is free to rotate about a frictionless pivot located L/3 from one end. The rod is released from rest incrementally away from being perfectly vertical, resulting in the rod rotating clockwise about the pivot. When the rod is horizontal, what is the magnitude of the tangential acceleration of its center of mass?

Anonymous User tag : Physics 14 Aug, 2019 1 Answer 84 views

A triangular frame consists of three identical rods, each of mass m and length l. It rests upright on a horizontal smooth surface with its lower right corner against a stop about which the frame could pivot. A horizontal force of magnitude F is applied to the upper corner of the frame as shown in the figure. What is the largest value of F may have without causing the frame to pivot upward about the stop?

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A triangular frame consists of three identical rods, each of mass m and length l. It rests upright on a horizontal smooth surface with its lower right corner against a stop about which the frame could pivot. A horizontal force of magnitude F is applied to the upper corner of the frame as shown in the figure. What is the largest value of F may have without causing the frame to pivot upward about the stop?

 

Anonymous User tag : Physics 11 Aug, 2019 1 Answer 60 views

A uniform, solid cylinder having mass M and radius R is pulled by a horizontal force F acting through the center as shown. The cylinder rolls to the right without slipping. What is the magnitude of the force of friction between the cylinder and the ground?

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A uniform, solid cylinder having mass M and radius R is pulled by a horizontal force F acting through the center as shown. The cylinder rolls to the right without slipping. What is the magnitude of the force of friction between the cylinder and the ground?

Anonymous User tag : Physics 11 Aug, 2019 1 Answer 73 views

A parachutist drops freely

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A parachutist drops freely from an aeroplane for 8s before the parachute opens out.then he descends with a retardation of 2ms reaching the ground with a velocity of 6ms.find the height from which he falls

Anonymous User tag : Physics 04 Aug, 2019 1 Answer 65 views

A ball of density p0 falls from rest from point P onto the surface of a liquid of density p0 in time T. It enters the liquid stops moves up and returns to P in a total time 3T. Neglect viscosity, surface tension and splashing. The ratio p/p0 is equal to

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A ball of density p0 falls from rest from point P onto the surface of a liquid of density p0 in time T. It enters the liquid stops moves up and returns to P in a total time 3T. Neglect viscosity, surface tension and splashing. The ratio p/p0 is equal to

Anonymous User tag : Physics 01 Aug, 2019 1 Answer 62 views

An engine whistling at a constant frequency n0 and moving with a constant velocity goes past a stationary observer. As the engine crosses him, the frequency of the sound heard by him changes by a factor f. The actual difference in the frequency of the sound heard by him before and after the engine across him is

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An engine whistling at a constant frequency n0 and moving with a constant velocity goes past a stationary observer. As the engine crosses him, the frequency of the sound heard by him changes by a factor f. The actual difference in the frequency of the sound heard by him before and after the engine across him is

Anonymous User tag : Physics 01 Aug, 2019 0 Answer 56 views

A flat coil of area A and n turns is placed at the centre of a ring of radius r (r2 >> A) and resistance R. The two are co-planar when current in the coil increases from zero to i, the total charge circulating in the ring is

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A flat coil of area A and n turns is placed at the centre of a ring of radius r (r2 >> A) and resistance R. The two are co-planar when current in the coil increases from zero to i, the total charge circulating in the ring is?

Ashish Maurya tag : Physics 01 Aug, 2019 1 Answer 144 views

The focal length of the objective of a microscope is 2cm.The final image of object placed 3cm from the objective is formed at least distance of the distinct vision.if the magnifying power is 10 then calculate focal length of eyepiece.

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The focal length of the objective of a microscope is 2cm.The final image of object placed 3cm from the objective is formed at least distance of the distinct vision.if the magnifying power is 10 then calculate focal length of eyepiece.

Anonymous User tag : Physics 08 Jul, 2019 1 Answer 64 views

A copper rod of length L and mass m is sliding down a smooth inclined plane of inclination theta angle with a constant speed v.  A current I is flowing in perpendicular to the plane of diagram inwards. A vertically upward magnetic field B exists in this region. The magnitude of the required magnetic B is?

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A copper rod of length L and mass m is sliding down a smooth inclined plane of inclination  with a constant speed v.  A current I is flowing in perpendicular to the plane of diagram inwards. A vertically upward magnetic field B exists in this region. The magnitude of the required magnetic B is?

 

 

Anonymous User tag : Physics 07 Jul, 2019 1 Answer 67 views

Two blocks of masses 6kg and 4kg connected by a  rope of mass 4 kg are resting on frictionless floor as shown. If a constant force of 21 Newton is applied to 6 kg block, tension (In N) in the rope at point B is (CB : BA = 1 : 1)

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Two blocks of masses 6kg and 4kg connected by a  rope of mass 4 kg are resting on frictionless floor as shown. If a constant force of 21 Newton is applied to 6 kg block, tension (In N) in the rope at point B is (CB : BA = 1 : 1)

Anonymous User tag : Physics 01 Jul, 2019 1 Answer 184 views

A parallel plate capacitor is made of two circular plates separated by a distance of 5 mm and with a dielectric of dielectric constant 2.2 between them. When the electric field in the dielectric is 10^4 V/m, the charge density of the positive plate will be close to

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A parallel plate capacitor is made of two circular plates separated by a distance of 5 mm and with a dielectric of dielectric constant 2.2 between them. When the electric field in the dielectric is 10000 V/m, the charge density of the positive plate will be close to

Jitendra Mishra tag : Physics 17 Jun, 2019 1 Answer 65 views

rotation

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The mi of a rod abt an axis through its axis and perpendicular to it is 1/12ml^2 the rod bent in middle so that 2 halves make angle 60 mi of bent rod abt same axis is

Anonymous User tag : Physics 05 Jun, 2019 0 Answer 58 views

rotation

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a square is made by joining 4 rods each of mass m and length its mi abt an axis pq in its plane and is passing through 1 of its end

Anonymous User tag : Physics 05 Jun, 2019 1 Answer 64 views

A water drop of 0.05cm3 is squeezed between two glass plates and spreads into area of 40cm2. If the surface tension of water is 70 dyne/cm then the normal force required to separate the glass plates from each other will be

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A water drop of 0.05cm3 is squeezed between two glass plates and spreads into area of 40cm2. If the surface tension of water is
70 dyne/cm then the normal force required to separate the glass plates from each other will be

Anonymous User tag : Physics 30 May, 2019 1 Answer 59 views

There is a circular tube in a vertical plane. Two liquids which do not mix and of densities d1 and d2 are filled in the tube. Each liquid subtends 90° angle at centre. Radius joining their interface makes an angle α with vertical. Ratio of d1/d2

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There is a circular tube in a vertical plane. Two liquids which do not mix and of densities d1 and d2 are filled in the tube. Each liquid subtends 90° angle at centre. Radius joining their interface makes an angle α with vertical. Ratio of d1/d2

Anonymous User tag : Physics 20 May, 2019 1 Answer 83 views

From a tower of height H, a particle is thrown vertically upwards with a speed U. The time taken by the particle, to hit the ground, is n times that taken by it to reach the highest point of its path. The relation between H, u and n is ?

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From a tower of height H, a particle is thrown vertically upwards with a speed U. The time taken by the particle, to hit the ground, is n times that taken by it to reach the highest point of its path. The relation between H, u and n is ?

Anonymous User tag : Physics 18 May, 2019 1 Answer 153 views

The radiation corresponding to 3 → 2 transition of hydrogen atom falls on a metal surface to produce photoelectrons. These electrons are made to enter a magnetic field of 3 × 10−4 T. If the radius of the largest circular path followed by these electrons is 10.0 mm, the work function of the metal is close to :

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The radiation corresponding to 3 → 2 transition of hydrogen atom falls on a metal surface to produce photoelectrons. These electrons are made to enter a magnetic field of 3 × 10−4 T. If the radius of the largest circular path followed by these electrons is 10.0 mm, the work function of the metal is close to ?

Anonymous User tag : Physics 12 May, 2019 1 Answer 66 views

A bird is sitting on the top of a vertical pole 20 m high and its elevation from a point O on the ground is 45°. It flies off horizontally straight away from the point O. After one second, the elevation of the bird from O is reduced to 30°. Then the speed (in m/s) of the bird is:

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A bird is sitting on the top of a vertical pole 20 m high and its elevation from a point O on the ground is 45°. It flies off horizontally straight away from the point O. After one second, the elevation of the bird from O is reduced to 30°. Then the speed (in m/s) of the bird is?

Anonymous User tag : Physics 11 May, 2019 1 Answer 76 views

The coercivity of a small magnet where the ferromagnet gets demagnetized is 3 × 10^3 A m−1 . The current required to be passed in a solenoid of length 10 cm and number of turns 100, so that the magnet gets de magnetised when inside the solenoid, is?

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The coercivity of a small magnet where the ferromagnet gets demagnetized is 3 × 10^3 A m−1 . The current required to be passed in a solenoid of length 10 cm and number of turns 100, so that the magnet gets de magnetised when inside the solenoid, is?

Anonymous User tag : Physics 09 May, 2019 1 Answer 90 views

A parallel plate capacitor is made of two circular plates separated by a distance of 5 mm and with a dielectric of dielectric constant 2.2 between them. When the electric field in the dielectric is 3 × 104 V/m, the charge density of the positive plate will be close to ?

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A parallel plate capacitor is made of two circular plates separated by a distance of 5 mm and with a dielectric of dielectric constant 2.2 between them. When the electric field in the dielectric is 3 × 10^4 V/m, the charge density of the positive plate will be close to ?

Anonymous User tag : Physics 09 May, 2019 0 Answer 58 views

a body is thrown vertically upward from a point 125 m above ground it goes up to a max height of 250m above ground and passes through a on its downward journey the velocity of body when it is at a height of 70m above ground

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a body is thrown vertically upward from a point 125 m above ground it goes up to a max height of 250m above ground and passes through a on its downward journey the velocity of body when it is at a height of 70m above ground

Anonymous User tag : Physics 08 May, 2019 1 Answer 307 views

WORK

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A MACHINE ,RATED 150 W, CHANGES ITS VELOCITY OF A 10KG MASS FROM 4 TO 10 M/S IN 4S.THE EFFICIENCY OF MACHINE IS NEARLY

Anonymous User tag : Physics 05 May, 2019 0 Answer 72 views

Consider two containers A and B containing identical gases at the same pressure, volume and temperature. The gas in container A is compressed to half of its original volume isothermally while the gas in container B is compressed to half of its original value adiabatically. The ratio of final pressure of gas in B to that of gas in A is ?

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Consider two containers A and B containing identical gases at the same pressure, volume and temperature. The gas in container A is compressed to half of its original volume isothermally while the gas in container B is compressed to half of its original value adiabatically. The ratio of final pressure of gas in B to that of gas in A is ?

Anonymous User tag : Physics 04 May, 2019 0 Answer 55 views

The relative density of a metal may be found by hanging a block of the metal from a spring balance and noting that in air the balance reads (5 ± 0.05) N while in water it reads (4 ± 0.05)N. The relative density would be quoted as:

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The relative density of a metal may be found by hanging a block of the metal from a spring balance and noting that in air the balance reads (5 ± 0.05) N while in water it reads (4 ± 0.05)N. The relative density would be quoted as:

Anonymous User tag : Physics 04 May, 2019 1 Answer 143 views

A shell is fired at a speed of 200 m/s at an angle of 37° above horizontal from top of a tower 80m high. At the same instant another shell was fired from a jeep travelling away from the tower at a speed of 10 m/s as shown. The velocity of this shell relative to jeep is 250 m/s at an angle of 53° with horizontal. Find the time (in sec) taken by the two shells to come closest?

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A shell is fired at a speed of 200 m/s at an angle of 37° above horizontal from top of a tower 80m high. At the same instant another shell was fired from a jeep travelling away from the tower at a speed of 10 m/s as shown. The velocity of this shell relative to jeep is 250 m/s at an angle of 53° with horizontal. Find the time (in sec) taken by the two shells to come closest.

Anonymous User tag : Physics 04 May, 2019 1 Answer 67 views

work

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a body freely falls from certain height onto ground in time t during first 1/3rd of time interval it gains ake1 and during last 1/3 rd of intervalit gains ke2 the ratio of ke1/ke2 is

Anonymous User tag : Physics 02 May, 2019 1 Answer 71 views

law of motion

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a mass of 3kg descending vertically downward supports a mass 2 kg by means of light string passing over a pulley at end of 5 sec the string breaks how much higher 2kg mass will go

Anonymous User tag : Physics 30 Apr, 2019 1 Answer 94 views

In a uniform electric field, a cube of side 1 cm is placed. The total energy stored in the cube is 8.85μJ. The electric field is parallel to four of the faces of the cube. The electric flux through any one of the remaining two faces is.

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In a uniform electric field, a cube of side 1 cm is placed. The total energy stored in the cube is 8.85μJ. The electric field is parallel to four of the faces of the cube. The electric flux through any one of the remaining two faces is.

Anonymous User tag : Physics 28 Apr, 2019 1 Answer 121 views

Suppose that two heat engines are connected in series, such that the heat exhaust of the first engine is used as the heat input of the second engine as shown in figure. The efficiencies of the engines are n1 and n2, respectively. The net efficiency of the combination is given by?

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Suppose that two heat engines are connected in series, such that the heat exhaust of the first engine is used as the heat input of the second engine as shown in figure. The efficiencies of the engines are n1 and n2, respectively. The net efficiency of the combination is given by?

Anonymous User tag : Physics 28 Apr, 2019 1 Answer 65 views

A magnet is suspended in such a way when it oscillates in the horizontal plane. It makes 20 oscillations per minute at a place where dip angle is 30 and 15 oscillations per min at a place where dip angle is 60 . Find the ratio of the total earth's magnetic field at the two places?

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A magnet is suspended in such a way when it oscillates in the horizontal plane. It makes 20 oscillations per minute at a place where dip angle is 30 and 15 oscillations per min at a place where dip angle is 60 . Find the ratio of the total earth's magnetic field at the two places?

Anonymous User tag : Physics 26 Apr, 2019 0 Answer 96 views

A simple pendulum is suspended in a lift which 5. is going up with an acceleration 5 m/s2. An electric field of magnitude 5 N/C and directed vertically upward is also present in the lift. The charge of the bob is 1 mC and mass is 1 mg. Taking g = p2 and length of the simple pendulum 1m, the time period of the simple pendulum is

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A simple pendulum is suspended in a lift which 5. is going up with an acceleration 5 m/s^2. An electric field of magnitude 5 N/C and directed vertically upward is also present in the lift. The charge of the bob is 1 mC and mass is 1 mg. Taking g =  and length of the simple pendulum 1m, the time period of the simple pendulum is

Anonymous User tag : Physics 20 Apr, 2019 1 Answer 119 views

A sounding body emitting a frequency of 150 Hz is dropped from a height. During its fall under gravity it crosses a balloon moving upwards with a constant velocity of 2m/s one second after it started to fall. The difference in the frequency observed by the man in balloon just before and just after crossing the body will be: (given that -velocity of sound = 300m/s; g = 10m/s2 )

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A sounding body emitting a frequency of 150 Hz is dropped from a height. During its fall under gravity it crosses a balloon moving upwards with a constant velocity of 2m/s one second after it started to fall. The difference in the frequency observed by the man in balloon just before and just after crossing the body will be:

Given that -velocity of sound = 300m/s; g = 10m/s2.

(A) 4

(B) 6

(C) 8

(D) 12

Kirti Gulati tag : Physics 16 Apr, 2019 1 Answer 53 views

A passenger is standing d distance away from a bus. The bus begins to move with constant acceleration a. To catch the bus, the passenger runs at a constant speed u towards the bus. What must be the minimum speed of the passenger so that he may catch the bus?

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A passenger is standing d distance away from a bus. The bus begins to move with constant acceleration a. To catch the bus, the passenger runs at a constant speed u towards the bus. What must be the minimum speed of the passenger so that he may catch the bus?

Anonymous User tag : Physics 15 Apr, 2019 1 Answer 79 views

A driver takes 0.30 s to apply the brakes after he sees a need for it. This is called the reaction time of the driver. If he is driving a car at a speed of 54 km/h and the brakes cause a deceleration of 5.0m/s2, find the distance travelled by the car after he sees the need to put the brakes on ?

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A driver takes 0.30 s to apply the brakes after he sees a need for it. This is called the reaction time of the driver. If he is driving a car at a speed of 54 km/h and the brakes cause a deceleration of 5.0m/s2, find the distance travelled by the car after he sees the need to put the brakes on ?

Anonymous User tag : Physics 15 Apr, 2019 1 Answer 61 views

The force of repulsion between two point charges is F, when these are at a distance of 1 m. Now the point charges are replaced by spheres of radii 25 cm having the charge same as that of point charges. The distance between their centres is 1 m, then compare the force of repulsion in two cases.

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The force of repulsion between two point charges is F, when these are at a distance of 1 m. Now the point charges are replaced by spheres of radii 25 cm having the charge same as that of point charges. The distance between their centres is 1 m, then compare the force of repulsion in two cases.

Anonymous User tag : Physics 13 Apr, 2019 1 Answer 584 views

A particle is moving along a straight line along x-axis with an initial velocity of 2 m/s towards positive x-axis. A constant acceleration of 0.5 m/s2 towards negative x-axis starts acting on particle at t=0. Find velocity (in m/s) of particle at t = 2s.

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A particle is moving along a straight line along x-axis with an initial velocity of 2 m/s towards positive x-axis. A constant acceleration of 0.5 m/s2 towards negative x-axis starts acting on particle at t=0. Find velocity (in m/s) of particle at t = 2s.

Rahul Kumar tag : Physics 12 Apr, 2019 1 Answer 60 views

A body is thrown up with a speed 49 m/s. It travels 5 m in the last second of its upward journey. If the same body is thrown up with a velocity 98 m/s, how much distance (in m) will it travel in the last second. (g = 10 m/s2)?

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A body is thrown up with a speed 49 m/s. It travels 5 m in the last second of its upward journey. If the same body is thrown up with a velocity 98 m/s, how much distance (in m) will it travel in the last second. (g = 10 m/s2)?

Rahul Kumar tag : Physics 12 Apr, 2019 1 Answer 78 views

A solid sphere of mass M and radius R is surrounded by a spherical shell of same mass M and radius 2R as shown. A small particle of mass m is released from rest from a height h (<<R) above the shell. There is a hole in the shell.

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A solid sphere of mass M and radius R is surrounded by a spherical shell of same mass M and radius 2R as shown. A small particle of mass m is released from rest from a height h (<<R) above the shell. There is a hole in the shell.

Devendra Yadav tag : Physics 12 Apr, 2019 0 Answer 55 views

If the law of gravitation be such that the force of attraction between two particles vary inversely as the 5/2th power of their separation, then the graph of orbital velocity v0 plotted against the distance r of a satellite from the earth's centre on a log-log scale is shown alongside. The slope of line will be

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If the law of gravitation be such that the force of attraction between two particles vary inversely as the 5/2th power of their separation, then the graph of orbital velocity v0 plotted against the distance r of a satellite from the earth's centre on a log-log scale is shown alongside. The slope of line will be

Ashish Yadav tag : Physics 12 Apr, 2019 1 Answer 55 views

An open glass tube is immersed in mercury in such a way that a length of 8 cm extends above the mercury level. The open end of the tube is then closed and sealed and the tube is raised vertically up by additional 46 cm. What will be length of the air column above mercury in the tube now?

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An open glass tube is immersed in mercury in such a way that a length of 8 cm extends above the mercury level. The open end of the tube is then closed and sealed and the tube is raised vertically up by additional 46 cm. What will be length of the air column above mercury in the tube now?

Anonymous User tag : Physics 10 Apr, 2019 1 Answer 54 views

A box of mass m is initially at rest on a horizontal surface. A constant horizontal force of mg/2 is applied to the box directed to the right. The coefficient of friction of the surface changes with the distance pushed as µ = µ0x where x is the distance from the initial location. For what distance is the box pushed until it comes to rest again?

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A box of mass m is initially at rest on a horizontal surface. A constant horizontal force of mg/2 is applied to the box directed to the right. The coefficient of friction of the surface changes with the distance pushed as µ = µ0x where x is the distance from the initial location. For what distance is the box pushed until it comes to rest again?

Anonymous User tag : Physics 09 Apr, 2019 1 Answer 68 views

The mean lives of a radioactive sample are 30 years and 60 years for alpha-emission and beta–emission respectively. If the sample decays both by alpha–emission and beta–emission simultaneously, the time after which, only one-fourth of the sample remain is 

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The mean lives of a radioactive sample are 30 years and 60 years for alpha-emission and beta–emission respectively. If the sample decays both by alpha–emission and beta–emission simultaneously, the time after which, only one-fourth of the sample remain is 

Anonymous User tag : Physics 07 Apr, 2019 1 Answer 268 views

A spherical conductor of radius 3 m is charged to a potential of 90 V. It is now placed inside another hollow spherical conductor of radius 6 m. Calculate the potential of bigger sphere if the smaller sphere is made to touch the bigger sphere?

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A spherical conductor of radius 3 m is charged to a potential of 90 V. It is now placed inside another hollow spherical conductor of radius 6 m. Calculate the potential of bigger sphere if the smaller sphere is made to touch the bigger sphere?

Anonymous User tag : Physics 25 Mar, 2019 1 Answer 66 views

A mass (M) is split into two parts (m) and (M–m). Which are then separated by a certain distance. What ratio m M will maximise the gravitational force between the parts ?A mass (M) is split into two parts (m) and (M–m). Which are then separated by a certain distance. What ratio m/ M will maximise the gravitational force between the parts ?

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A mass (M) is split into two parts (m) and (M–m). Which are then separated by a certain distance. What ratio m M will maximise the gravitational force between the parts ?A mass (M) is split into two parts (m) and (M–m). Which are then separated by a certain distance. What ratio m/ M will maximise the gravitational force between the parts ?

Anonymous User tag : Physics 16 Mar, 2019 1 Answer 66 views

Two stationary particles of masses M1 and M2 are at a distance 'd' apart. A third particle lying on the line joining the particles, experiences no resultant gravitational forces. What is the distance of this particle from M1 ?

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Two stationary particles of masses M1 and M2 are at a distance 'd' apart. A third particle lying on the line joining the particles, experiences no resultant gravitational forces. What is the distance of this particle from M1 ?

Anonymous User tag : Physics 15 Mar, 2019 1 Answer 364 views

An electrical cable of copper has just one wire of radius 9 mm. Its resistance is 5 ohm. This single copper wire of the cable is replaced by 6 different well insulated copper wires each of radius 3 mm. The total resistance of the cable will now be equal to?

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An electrical cable of copper has just one wire of radius 9 mm. Its resistance is 5 ohm. This single copper wire of the cable is replaced by 6 different well insulated copper wires each of radius 3 mm. The total resistance of the cable will now be equal to?

Anonymous User tag : Physics 04 Feb, 2019 1 Answer 115 views

A short bar magnet with its north pole facing north forms a neutral point at P in the horizonatal plane. If the magnet is rotated by 90° in the horizontal plane, the net magnetic induction at P is (Horizontal component of earth's magnetic field = BH )

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A short bar magnet with its north pole facing north forms a neutral point at P in the horizonatal plane. If the magnet is rotated by 90° in the horizontal plane, the net magnetic induction at P is (Horizontal component of earth's magnetic field = BH )

Ashish Yadav tag : Physics 04 Feb, 2019 1 Answer 833 views

A thermally insulated vessel contains an ideal gas of molecular mass M and ratio of specific heats g. It is moving with speed v and it's suddenly brought to rest. Assuming no heat is lost to the surroundings, its temperature increases by:

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A thermally insulated vessel contains an ideal gas of molecular mass M and ratio of specific heats g. It is moving with speed v and it's suddenly brought to rest. Assuming no heat is lost to the surroundings, its temperature increases by:

Anonymous User tag : Physics 01 Feb, 2019 1 Answer 140 views

A particle performs S.H.M. of amplitude A along a straight line. At two positions of the particle, the ratio of speeds is 1/2 and that of potential energy is 1/2 also. Then one position of them (distance from mean position) nearest to the extreme is :

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A particle performs S.H.M. of amplitude A along a straight line. At two positions of the particle, the ratio of speeds is 1/2 and that of potential energy is 1/2 also. Then one position of them (distance from mean position) nearest to the extreme is :

Anonymous User tag : Physics 01 Feb, 2019 0 Answer 70 views

A particle is projected from ground with an initial velocity 20 m/sec making an angle 60° with horizontal. If R1 and R2 are radius of curvatures of the particle at point of projection and highest point respectively,find the value of R1/R2?

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A particle is projected from ground with an initial velocity 20 m/sec making an angle 60° with horizontal. If R1 and R2 are radius of curvatures of the particle at point of projection and highest point respectively,find the value of R1/R2?

Devendra Yadav tag : Physics 18 Jan, 2019 1 Answer 62 views

The bob of a simple pendulum is a spherical hollow ball filled with water. A plugged hole near the bottom of the oscillating bob gets suddenly unplugged. During observation, till water is coming out, the time period of oscillation would?

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The bob of a simple pendulum is a spherical hollow ball filled with water. A plugged hole near the bottom of the oscillating bob gets suddenly unplugged. During observation, till water is coming out, the time period of oscillation would?

Anonymous User tag : Physics 15 Jan, 2019 1 Answer 63 views

A coin is placed on a horizontal platform which undergoes vertical simple harmonic motion of angular frequency w. The amplitude of oscillation is gradually increased. The coin will leave contact with the platform for the first time

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A coin is placed on a horizontal platform which undergoes vertical simple harmonic motion of angular frequency w. The amplitude of oscillation is gradually increased. The coin will leave contact with the platform for the first time

Anonymous User tag : Physics 15 Jan, 2019 1 Answer 126 views

Two protons of equal kinetic energies enter a region of uniform magnetic field. The first proton enters normal to the field direction while the second enters at 30 to the field direction. Name the trajectories followed by them.

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Two protons of equal kinetic energies enter a region of uniform magnetic field. The
first proton enters normal to the field direction while the second enters at 30 degree to the field direction. Name the trajectories followed by them.

Naveen Singh tag : Physics 03 Jan, 2019 1 Answer 362 views

if a dielectric slab of a thickness t and area A is inserted in between the plates of a parallel plate capacitor of plate area A and distance between the plates d (d>t) then find out capacitance of system?What do you predict about the dependence of capacitance on location of slab?

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if a dielectric slab of a thickness t and area A is inserted in between the plates of a parallel plate capacitor of plate area A and distance between the plates d (d>t) then find out capacitance of system?What do you predict about the dependence of capacitance on location of slab?

Anonymous User tag : Physics 18 Dec, 2018 0 Answer 106 views

State Huygens Principle. Using the geometrical construction of secondary wavelets, explain the refraction of a plane wavefront incident at a plane surface. Hence verify the Snell’s law. Illustrate with the help of a diagram the action of (i) Convex lens and (ii) concave mirror on a plane wavefront incident on it.

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State Huygens Principle. Using the geometrical construction of secondary wavelets, explain the refraction of a plane wavefront incident at a plane surface. Hence verify the Snell’s law. Illustrate with the help of a diagram the action of (i) Convex lens and (ii) concave mirror on a plane wavefront incident on it.

Anonymous User tag : Physics 16 Dec, 2018 0 Answer 310 views

Define capacitance. Derive an expression for the capacitance of a parallel plate capacitor. How will the capacitance of the capacitor be affected if a conducting slab of some thickness is partially filled in the space between two plates.

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Define capacitance. Derive an expression for the capacitance of a parallel plate capacitor. How will the capacitance of the capacitor be affected if a conducting slab of some thickness is partially filled in the space between two plates.

Anonymous User tag : Physics 15 Dec, 2018 1 Answer 76 views

At night approximately 500 photons per second must enter an unaided human eye for an object to be seen. A light bulb emits about 5*10^18 photons per second uniformly in all directions. The radius of the pupil of the eye is about 4 * 10 ^-3 meters. What is the maximum distance from which the bulb could be seen?

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At night approximately 500 photons per second must enter an unaided human eye for an object to be seen. A light bulb emits about photons per second uniformly in all directions. The radius of the pupil of the eye is about 

meters. What is the maximum distance from which the bulb could be seen?

Preeti Rai tag : Physics 14 Dec, 2018 1 Answer 65 views

In a car race sound signals emitted by the two cars are detected by the detectors on the straight track at the end point of the race. Frequency observed are 330 Hz and 360 Hz and the original frequency is 300 Hz of both cars. Race ends with the separation of 100m between the cars. Assume both cars move with constant velocity and velocity of sound is 330 m/s. Find the time (in second) taken by wining car?

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In a car race sound signals emitted by the two cars are detected by the detectors on the straight track at the end point of the race. Frequency observed are 330 Hz and 360 Hz and the original frequency is 300 Hz of both cars. Race ends with the separation of 100m between the cars. Assume both cars move with constant velocity and velocity of sound is 330 m/s. Find the time (in second) taken by wining car?

Devendra Yadav tag : Physics 13 Dec, 2018 1 Answer 166 views

A charge is distributed uniformly over a ring of radius a.Obtain an expression for electric intensity E at a point on the axis of the ring.Hence show that for the points at large distance from the ring, it behave like a point charge.

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A charge is distributed uniformly over a ring of radius a.Obtain an expression for electric intensity E at a point on the axis of the ring.Hence show that for the points at large distance from the ring, it behave like a point charge.

Anonymous User tag : Physics 12 Dec, 2018 0 Answer 216 views

A parallel plate condenser with a dielectric of dielectric constant K between the plates has a capacity C and is charged to a potential V volt. The dielectric slab is slowly removed from between the plates and then reinserted. The net work done by the system in this process is

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A parallel plate condenser with a dielectric of dielectric constant K between the plates has a capacity C and is charged to a potential V volt. The dielectric slab is slowly removed from between the plates and then reinserted. The net work done by the system in this process is

Anonymous User tag : Physics 14 Nov, 2018 1 Answer 88 views

An electrical cable of copper has just one wire of radius 9mm. Its resistance is 5 ohm. This single copper wire of the cable is replaced by 6 different well insulated copper wires each of radius 3 mm. The total resistance of the cable will now be equal to

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 An electrical cable of copper has just one wire of radius 9mm. Its resistance is 5 ohm. This single copper wire of the cable is replaced by 6 different well insulated copper wires each of radius 3 mm. The total resistance of the cable will now be equal to?

Anonymous User tag : Physics 12 Nov, 2018 1 Answer 1407 views

In Young's double slit experiment, one of the slit is wider than other, so that amplitude of the light from one slit is double of that from other slit. If Im be the maximum intensity, the resultant intensity I when they interfere at phase difference f is given by

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In Young's double slit experiment, one of the slit is wider than other, so that amplitude of the light from one slit is double of that from other slit. If  be the maximum intensity, the resultant intensity I when they interfere at phase difference f is given by

Anonymous User tag : Physics 30 Oct, 2018 1 Answer 291 views

Kepler’s second law states that the radius vector to a planet from the sun sweeps out equal areas in equal intervals of time. This law is a consequence of the conservation of: (a) Time (b) Mass (c) Angular momentum (d) Linear momentum

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Kepler’s second law states that the radius vector to a planet from the sun sweeps out equal areas in equal intervals of time.

This law is a consequence of the conservation of: (a) Time (b) Mass (c) Angular momentum (d) Linear momentum

Preeti Rai tag : Physics 19 Oct, 2018 1 Answer 62 views