An initially parallel cylindrical beam travels in a medium of refractive index  where  and  are positive constants and I is the intensity of the light beam. The intensity of the beam is decreasing with increasing radius.

As the beam enters the medium, it will

Anonymous User Physics Wave Optics 10 May, 2020 1 Answer 66 views

A transparent solid cylindrical rod has a refractive index of . It is surrounded by air. A light ray is incident at the mid-point of one end of the rod as shown in the figure

The incident angle θ for which the light ray grazes along the wall of the rod is

Anonymous User Physics Ray Optics 09 May, 2020 1 Answer 64 views

A long metallic bar is carrying heat from one of its ends to the other end under steady-state. The variation of temperature θ along the length x of the bar from its hot end is best described by which of the figures?

Anonymous User Physics Heat Transfer 09 May, 2020 1 Answer 54 views


Consider a rubber ball freely falling from a height h = 4.9 m onto a horizontal elastic plate. Assume that the duration of collision is negligible and the collision with the plate is totally elastic. Then what will be the velocity as a function of time and the height as function of time? 

Anonymous User Physics Work Power and Energy 09 May, 2020 1 Answer 69 views

A motor cycle starts from rest and accelerates along a straight path at 2 m/s2. At the starting point of the motor cycle there is a stationary electric siren. How far has the motor cycle gone when the driver hears the frequency of the siren at 94% of its value when the motor cycle was at rest? (Speed of sound = 330 ms-1).

Anonymous User Physics Work Power and Energy 09 May, 2020 1 Answer 63 views






An inductor of inductance L = 400 mH and resistors of resistances R1 = 2  and R2 = 2  are connected to a battery of emf 12 V as shown in the figure. The internal resistance of the battery is negligible. The switch S is closed at t = 0. What will be the potential drop across L as a function of time?

Anonymous User Physics Electromagnetic Induction & Alternating Current 09 May, 2020 1 Answer 70 views

In an experiment the angles are required to be measured using an instrument. 29 divisions of the main scale exactly coincide with the 30 divisions of the vernier scale. If the smallest division of the main scale is half-a-degree (= 0.5°), then the least count of the instrument will be 

Anonymous User Physics 09 May, 2020 1 Answer 57 views

Two wires are made of the same material and have the same volume. However wire 1 has cross-sectional area A and wire 2 has cross-sectional area 3A. If the length of wire 1 increases by ∆x on applying force F, how much force is needed to stretch wire 2 by the same amount?

Anonymous User Physics 09 May, 2020 1 Answer 60 views





Two identical glass rods S1 and S2 (refractive index = 1.5) have one convex end of radius of curvature 10 cm. They are placed with the curved surfaces at a distance d as shown in the figure, with their axes (shown by the dashed line) aligned. When a point source of light P is placed inside rod S1 on its axis at a distance of 50 cm from the curved face, the light rays emanating from it are found to be parallel to the axis inside S2.The distance d is

Ray optics

Anonymous User Physics Ray Optics 08 May, 2020 1 Answer 68 views

A point source S is placed at the bottom of a transparent block of height 10 mm and refractive index 2.72. It is immersed in a lower refractive index liquid as shown in the figure. It is found that the light emerging from the block to the liquid forms a circular bright spot of diameter 11.54 mm on the top of the block. The refractive index of the liquid is?

A point source S is placed at the bottom of a transparent block of height 10 mm and refractive index 2.72. It is immersed in a lower refractive index liquid as shown in the figure. It is found that the light emerging from the block to the liquid forms a circular bright spot of diameter 11.54 mm on the top of the block. The refractive index of the liquid is?

Anonymous User Physics Ray Optics 08 May, 2020 1 Answer 74 views


A bi-convex lens is formed with two thin plano convex lenses. Refractive index n of the first lens is 1.5 and that of the second lens is 1.2. Both the curved surfaces are of the same radius of curvature R = 14 cm. For this bi-convex lens, for an object distance of 40 cm, the image distance will be.

Anonymous User Physics Ray Optics 08 May, 2020 1 Answer 61 views

The image of an object, formed by a plano-convex lens at a distance of 8 m behind the lens, is real is one-third the size of the object. The wavelength of light inside the lens is 3 times the wavelength in free space.The radius of the curved surface of the lens is

Anonymous User Physics Ray Optics 08 May, 2020 1 Answer 64 views


A ball is dropped from a height of 20 m above the surface of water in a lake. The refractive index of water is 4/3. A fish inside the lake, in the line of fall of the ball, is looking at the ball. At an instant, when the ball is 12.8 m above the water surface, the fish sees the speed of ball as [Take g = 10 m/s2.]

Anonymous User Physics Ray Optics 08 May, 2020 1 Answer 61 views


In an experiment to determine the focal length (f) of a concave mirror by the u-v method, a student places the object pin A on the principal axis at a distance x from the pole P. The student looks at the pin and its inverted image from a distance keeping his/her eye in line with PA. When the student shifts his/her eye towards left, the image appears to the right of the object pin. Then

Anonymous User Physics Ray Optics 08 May, 2020 1 Answer 64 views

 A thin lens has a focal length f and its aperture has a diameter d. It forms an image of intensity I. Now, the outer part extending from R/2 to R is blackened. The focal length of the lens and intensity of image becomes/remain (R = radius of aperture = d/2 )

Anonymous User Physics Ray Optics 08 May, 2020 1 Answer 62 views



 

The upper half of an inclined plane with inclination  is perfectly smooth while the lower half is rough. A body starting from rest at the top will again come to rest at the bottom if the coefficient of friction for the lower half is given by

Anonymous User Physics 08 May, 2020 1 Answer 58 views



 

Consider a roller coaster with a circular loop. A roller coaster car starts from rest from the top of a hill which is 5 m higher than the top of the loop. It rolls down the hill and through the loop. What must the radius of the loop be so that the passengers of the car will feel at highest point, as if they have their normal weight?

Anonymous User Physics 08 May, 2020 1 Answer 304 views

One end of a light rope is tied directly to the ceiling. A man of mass M initially at rest on the ground starts climbing the rope hand over hand upto a height l. From the time he starts at rest on the ground to the time he is hanging at rest at a height l, how much work was done on the man by the rope?

Anonymous User Physics 08 May, 2020 1 Answer 563 views

A car is moving along a hilly road as shown (side view). The coefficient of static friction between the tyres and pavement is constant and the car maintains a steady speed. If, at one of the points shown the driver applies the brakes as hard as possible without making the tyres slip, the magnitude of the frictional force immediately after the brakes are applied will be maximum if the car was at

Anonymous User Physics 08 May, 2020 1 Answer 412 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  where x is the distance from the initial location. For what distance is the box pushed until it comes to rest again?

Anonymous User Physics 08 May, 2020 1 Answer 65 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.

What time will it take to move from A to B?

Anonymous User Physics 07 May, 2020 1 Answer 63 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.

In what time will it enter the hole at A :–

Anonymous User Physics 07 May, 2020 1 Answer 68 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

Anonymous User Physics 07 May, 2020 1 Answer 63 views

A particle is projected from point A, that is at a distance 4R from the centre of the Earth, with speed v1 in a direction making 30 with the line joining the centre of the Earth and point A, as shown. Find the speed v1 of particle (in m/s) if particle passes grazing the surface of the earth. Consider gravitational interaction only between these two.

Anonymous User Physics 07 May, 2020 1 Answer 165 views

Gravitational potential difference between a point on surface of planet and another point 10 m above is 4 J/kg. Considering gravitational field to be uniform, how much work is done in moving a mass of 2 kg from the surface to a point 5m above the surface?

Anonymous User Physics 07 May, 2020 1 Answer 55 views




The escape velocity for a planet is Ve. A particle starts from rest at a large distance from the planet, reaches the planet only under gravitational attraction, and passes through a smooth tunnel through its centre. Its speed at the centre of the planet will be

Anonymous User Physics 07 May, 2020 1 Answer 60 views


Two moles of ideal helium gas are in a rubber balloon at 30oC. The balloon is fully expandable and can be assumed to require no energy in its expansion. The temperature of the gas in the balloon is slowly changed to 35oC. The amount of heat required in raising the temperature is nearly (take R = 8.31 J/mol.K)

Anonymous User Physics Thermodynamics 07 May, 2020 1 Answer 76 views