Microscopic group of Physics dealt with the study of ____________.

(a)

classical physics

(b)

statistical mechanics

(c)

fluid mechanics

(d)

quantum physics

Retardation means ____________.

(a)

decreases with time

(b)

increases with time

(c)

increases and decreases

(d)

decreases and increases

The unit of momentum is ____________.

(a)

kg m s^-1

(b)

kg m² s^-2

(c)

kg m² s^-1

(d)

kg^-1 m² s^-1

When is the speed of a moving body doubled?

(a)

its acceleration is doubled

(b)

its momentum is doubled

(c)

its kinetic energy is doubled

(d)

its potential energy is doubled

A metal ball of mass 2 kg moving with speed of 36 km/h has a head on collision with a stationary ball of mass 3 kg. If after collision, both the balls move as a single mass, then the loss in K.E. due to collision is ________________.

(a)

100J

(b)

140J

(c)

40J

(d)

60J

The 10, cation of the centre of mass of a sphere is at ______________.

(a)

its top

(b)

its bottom

(c)

geometric centre

(d)

all the above

Three particles, each of mass m gram, are situated at the vertices of an equilateral triangle ABC of side I cm (as shown in the figure). The moment of inertia of the system about a line AX perpendicular to AB and in the plane of ABC, in gram cm² units will be _________________.

(a)

\(\frac { 3 }{ 4 } \)ml²

(b)

2 ml²

(c)

\(\frac { 5 }{ 4 } \)ml²

(d)

\(\frac { 3 }{ 2 } \)ml²

If net force acting on a body is zero, then the body is in ____________.

(a)

translational equilibrium

(b)

rotational equilibrium

(c)

both (c) and (b)

(d)

none

A satellite is moving around the Earth with speed v in a circular orbit of radius r. If the orbit radius is decreased by 1% its speed will _______.

(a)

increase by 1%

(b)

increase by 0.5%

(c)

decrease by 1%

(d)

decrease by 0.5%

The modulus of rigidity of a liquid is _______.

(a)

zero

(b)

1

(c)

infinite

(d)

none of these