Two spherical rain drops with radii in the ratio 1 : 2 fall from a great height through the atmosphere. The ratio of their momenta after they have attained terminal velocity is

• 1 : 8

• 2 : 1

• 1 : 32

• 1 : 2

22.

The angle of dip at a place where horizontal and vertical components of Earth's magnetic field are equal is

• 45°

• 30°

• 0°

• 60°

The radiating power of a linear antenna of length l for a wave of wavelength is proportional to

• $\frac{\mathrm{l}}{\mathrm{\lambda }}$

• $\frac{{\mathrm{l}}^2}{{\mathrm{\lambda }}^2}$

• $\frac{1}{{\mathrm{\lambda }}^2}$

• $\frac{1}{\sqrt{\mathrm{\lambda }}}$

A ball falling in a lake of depth 400 m has a decrease of 0.2% in its volume at the bottom. The bulk modulus of the material of the ball is (in Nm^-2)

• 9.8 × 10⁹

• 9.8 × 10¹⁰

• 1.96 × 10⁹

• 9.8 × 10¹¹

Three capillary tubes of same length but internal radii 0.3 mm, 0.45 mm and 0.6 mm are connected in series and a liquid flows steadily through them. If the pressure difference across the third capillary is 8.1 mm of mercury, the pressure difference across the first capillary (in mm of mercury) is

• 16.2

• 32.4

• 129.6

• 2.025

A ring cut with an inner radius 4.85 cm and outer radius 4.95 cm is supported horizontally from one of the pans of a balance so that it comes in contact with the water in a vessel. If surface tension of water is 70 x 10^-3 Nm^-1,then the extra mass in the other pan required to pull the ring away from water is

• 2 g

• 3 g

• 4.4 g

• 15 g

If the temperatures of source and sink of a Carnot engine having efficiency η are each decreased by 100 K, then the efficiency

• remains constant

• becomes 1

• decreases

• increases

If the time taken by a hot body to cool from 50°C to 40°C is 10 min when the surrounding temperature is 25°C, then the time taken for it to cool from 40°C to 30°C when the surrounding temperature is 15°C, is

• 40 min

• 10 min

• 5 min

• 15 min

The p-V diagram of a gas system undergoing cyclic process is shown here. The work done during isobaric compression is

• 100 J

• 200 J

• 400 J

• 500 J

In a cyclic process, the amount of heat given to a system is equal to

• net increase in internal energy

• net work done by the system

• net decrease in internal energy

• net change in volume