JEE (Advanced) 2007 Paper-1

STATEMENT-1
In an elastic collision between two bodies, the relative speed of the bodies after collision is equal to the relative speed before the collision.
because
STATEMENT-2
In anelastic collision, the linear momentum of the system is conserved.

STATEMENT-1
The formula connecting u, v and f for a spherical mirror is valid only for mirrors whosesizes are very small compared to their radii of curvature.
because
STATEMENT-2
Lawsof reflection are strictly valid for plane surfaces, but not for large spherical surfaces.

STATEMENT-1
If the accelerating potential in an X-ray tube is increased, the wavelengths of the characteristic X-rays do not change.
because
STATEMENT-2
Whenanelectron beam strikes the target in an X-ray tube, part of the kinetic energy is converted into X-ray energy.

The ratio $$\frac{x_1}{x_2}$$ is

When disc B is brought in contact with disc A, they acquire a common angular velocity in time t. The averagefrictional torque on one disc by the other during this period is

The loss of kinetic energy during the above process is

The piston is now pulled out slowly and held at a distance 2L from the top. The pressure in the cylinder between its top and the piston will then be

While the piston is at a distance 2L from the top, the hole at the top is sealed. The piston is then released, to a position where it can stay in equilibrium. In this condition, the distance of the piston from the top is

The piston is taken completely out of the cylinder. The hole at the top is sealed. A water tank is brought below the cylinder and put in a position so that the water surface in the tank is at the same level as the top of the cylinder as shown in the figure. The density of the water is $$\rho$$. In equilibrium, the height H of the water column in the cylinder satisfies 

Some physical quantities are given in Column I and some possible SI units in which these quantities may be expressed are given in Column II. Match the physical quantities in Column I with the units in Column II and indicate your answer by darkening appropriate bubbles in the $$4 \times 4$$ matrix given in the ORS.