Physics Test - ...

A rod AD, consisting of three segments AB, BC and CD joined together, is hanging vertically from a fixed support at A. The lengths of the segments are respectively 0.1 m, 0.2 m and 0.15 m. The cross - section of the rod is uniform 10^-4 m². A weight of 10 kg is hung from D. Calculate the displacements of point D if Y_AB = 2.5 x 10¹⁰ N/m², Y_BC = 4 x 10¹⁰ N/m² and Y_CD = 1 x 10¹⁰ N/m². (Neglect the weight of the rod.)

Energy from the sun falls on the earth at a rate of 1353 W/m², which is known as solar constant, i.e., the power incident per unit area per second at the top of atmosphere. Find the r.m.s values of the electric and magnetic fields in the sunlight reaching the top of the atmosphere.

50 V battery is supplying a steady current of 10 amp when connected to an external resistor. If the efficiency of the battery at this current is 25%, then internal resistance of battery is:

A lens (μ = 1.5) is coated with a thin film of refractive index 1.2 in order to reduce the reflection from its surface at $\lambda =4800\AA$ . Find the minimum thickness of the film which will minimise the intensity of the reflected light. (Assume near normal incidence)

A block of mass m & charge q is released on a long smooth inclined plane. Magnetic field B is constant, uniform, horizontal and out of the plane of paper as shown. Find the time from start when block loses contact with the surface.

In the figure shown the acceleration of A is, \(\overrightarrow{\mathrm{a}_{\mathrm{A}}}=1515\),then the acceleration of B is : (A remains in contact with B)

Binding energy per nucleon versus mass number curve for nuclei is shown in figure. W, X, Y and Z are four nuclei indicated on the curve. The process that would release energy is:

Two bodies of same mass tied with an inelastic string of length l lie together on a horizontal surface. One a horizontal surface of them is projected vertically upwards with velocity $\sqrt{6gl}.$Find the maximum height up to which the centre of mass of system of the two masses rises.

A battery of internal resistance 4 $\Omega$ is connected to the network of resistances as shown in figure. In order that the maximum power can be delivered to the network, the value of R should be :

The speed of sound in hydrogen gas at N.T.P. is 1,328 m s^-1. What will be its value in air at N.T.P., if density of hydrogen is 1/16th that of air?