When a current of 5 mA is passed through a galvanometer having a coil of resistance 15Ω, it shows full scale deflection. The value of the resistance to be put in series with the galvanometer to convert it into a voltmeter of range 0 – 10V is?

Preeti Rai Physics 09 Dec, 2017 1 Answer 2298 views



For three events A, B and C, P(Exactly one of A or B occurs) = P(Exactly one of B or C occurs) = P (Exactly one of C or A occurs) = 1/ 4 and P(All the three events occur simultaneously) = 1 /16 . Then the probability that at least one of the events occurs, is?

Devendra Yadav Maths 08 Dec, 2017 0 Answer 68 views




The most abundant elements by mass in the body of a healthy human adult are: Oxygen (61.4%); Carbon (22.9%), Hydrogen (10.0%); and Nitrogen (2.6%). The weight which a 75 kg person would gain if all H atoms are replaced by 2H atoms is?

Devendra Yadav Physics 08 Dec, 2017 1 Answer 2265 views

A capacitance of 2 µF is required in an electrical circuit across a potential difference of 1.0 kV. A large number of 1 µF capacitors are available which can withstand a potential difference of not more than 300 V. The minimum number of capacitors required to achieve this is?

Devendra Yadav Physics 08 Dec, 2017 1 Answer 326 views


In a Young’s double slit experiment, slits are separated by 0.5 mm, and the screen is placed 150 cm away. A beam of light consisting of two wavelengths, 650 nm and 520 nm, is used to obtain interference fringes on the screen. The least distance from the common central maximum to the point where the bright fringes due to both the wavelengths coincide is

Preeti Rai Physics 08 Dec, 2017 1 Answer 677 views

A copper ball of mass 100 gm is at a temperature T. It is dropped in a copper calorimeter of mass 100 gm, filled with 170 gm of water at room temperature. Subsequently, the temperature of the system is found to be 75 C. T is given by: (Given : room temperature = 30 C, specific heat of copper = 0.1 cal/gm C)

Preeti Rai Physics 08 Dec, 2017 1 Answer 227 views


For three events A, B and C, P(Exactly one of A or B occurs) = P(Exactly one of B or C occurs) = P (Exactly one of C or A occurs) = 1 /4 and P(All the three events occur simultaneously) = 1/ 16 . Then the probability that at least one of the events occurs, is:

Devendra Yadav Maths 07 Dec, 2017 1 Answer 1306 views

Two reactions R1 and R2 have identical pre exponential factors. Activation energy of R1 exceeds that of R2 by 10kj /mol. if k1 and k2 are rate constants R1 and R2 respectively at 300 K, then In (K2/K1) is equal to? Given (R=8.314 J/mol K)

Preeti Rai Chemistry 07 Dec, 2017 2 Answer 680 views


The fallowing observations were taken for determine surface tension T of water by capillary method: diameter of capillary, D = 1.25 * 10^-2 m rise of water, h = 1.45* 10^-2m Using g = 9.80 m/s^2 and the simplified relation T = rhg/2*10^3 N/m, the possible error in surface tension is closest to?

Devendra Yadav Physics 07 Dec, 2017 1 Answer 398 views


A car is standing 200 m behind a truck which is also at rest.The two start moving at the same instant but the different forward accelerations.The truck has acceleration 2 m/s^2 and the car has acceleration 4m/s^2. The car will catch up with bus after a time?

Rahul Kumar Physics 12 Sep, 2017 1 Answer 1671 views





What will be the probability that at least one of the event occurs for three events A, B and C, P(Exactly one of A or B occurs) = P(Exactly one of B or C occurs) = P(Exactly one of C or A occurs) = 1/4 and P(All the three events occur simultaneously) = 1/16?

Anshul Kumar Singh Maths 02 Sep, 2017 1 Answer 1077 views


What will be the beat frequency of the resulting signal in Hz if A stationary source emits sound of frequency f = 492 Hz. The sound is reflected by a large car approaching the source with a speed of 2 m/s. The reflected signal is received by the soruce and superposed with the original (Given that the speed of sound in air is 330 m/s and the car reflects the sound at the frequency it has received)?

Preeti Rai Physics 31 Aug, 2017 3 Answer 224 views






What will be the value of T if A copper ball of mass 100 gm is at a temperature T. It is dropped in a copper calorimeter of mass 100 gm,filled with 170 gm of water at room temperature. Subsequently, the temperature of the system is found to be 750C. T is given by: (Given : room temperature = 300C, specific heat of copper = 0.1 cal/gm0C)?

Anshul Kumar Singh Physics 26 Aug, 2017 1 Answer 392 views


A compound ‘X’ reacts with a compound ‘Y’, to produce a colourless and odourless gas. The gas turns lime water milky. When ‘X’ reacts with methanol in the presences of concentrated H2SO4, a sweet smelling substance is produced. The molecular formula of the compound ‘X’

Anshul Kumar Singh Chemistry 09 Aug, 2017 0 Answer 542 views


The following observations were taken for determining surface tension T of water by capillary method: diameter of capillary, D = 1.25 *10^-2m rise of water, h = 1.45 *10^2m Using g = 9.80 m/s2 and the simplified relation T = (rhg*10^)/2 N/ m, the possible error in surface tension is closest to?

Rahul Kumar Physics 04 Aug, 2017 1 Answer 220 views



A rocket is launched normal to the surface of earth, away from the Sun, along the line joining the Sun and the Earth. The Sun is 3 *10^5 times heavier than the Earth and is at a distance 2.5 *10^4 times larger than the radius of the Earth. The escape velocity from Earth’s gravitational field is ve = 11.2 km /s The minimum initial (vs) required for the rocket to be able to leave the Sun-earth system is closest to(Ignore the rotation and revolution of the Earth and the presence of any other planet).

Rahul Kumar Physics 30 Jul, 2017 1 Answer 327 views

An electron in a hydrogen atom undergoes a transition from an orbit with quantum numebr ni to another with quantum number nf. Vi and Vf are respectively the initial and final potential energies of the electon. If vi/ vf =6.25, Then what is smallest possible nf is

Preeti Rai Chemistry 29 Jul, 2017 1 Answer 449 views