physics event prelims

One of the following quantities which one has dimensions different from the remaining three?

• a) Energy per unit volume

• b) Force per unit area

• c) Product of voltage and charge per unit volume

• d) Angular momentum per unit mass

Calculate the angular speed of the hour hand of the clock

• a) π/86400

• b) π/21600

• c) π/36000

• d) π/24800

E, m, J and G denote energy, mass, angular momentum and gravitational constant respectively. The dimensions of EJ²/m⁵ G² are same as of

• a) Angle

• b) Length

• c) Mass

• d) Time

A car is moving at a speed of 40 m/s on a circular track of radius 400 m, this speed is increasing at rate of 3 m/s. the acceleration of the car is

• a) 4

• b) 5

• c) 7

• d) 3

Viscous drag force depends on

• a) Size of body

• b) Velocity with which it moves

• c) Viscosity of fluid

• d) All of these

The value of escape speed from certain planet is 4 km/s. what will be the orbital speed of a satellite orbiting close to its surface?

• a) 3√2 km/s

• b) 3√2/4 km/s

• c) 2√3 km/s

• d) 2√2 km/s

The bulk modulus of an incompressible liquid is

• a) Zero

• b) Unity

• c) Infinity

• d) Between 0 and 1

Ploughing help to retain water by soil

• a) By creating capillaries

• b) By breaking capillaries

• c) By turning the soil upside down

• d) None of these

A spherical black body with a radius of 12cm radiates 450Watt power at 500K. If the radius was halved and the temperature doubled, the power radiated in watt would be

• a) 225

• b) 450

• c) 1000

• d) 1800

Which of the following laws of thermodynamics defines internal energy?

• a) Zeroth law

• b) Second law

• c) First law

• d) Third law