PART - 2 CH - 8 Mechanical Properties of Solids — Physics STD 11 Science — Question

How is a heat engine different from a refrigerant?

Suppose a charged particle moves with a velocity v near a wire carrying an electric current. A magnetic force, therefore, acts on it. If the same particle is seen from a frame moving with velocity v in the same direction, the charge will be found at rest. Will the magnetic force become zero in this frame? Will the magnetic field become zero in this frame?

If the sum of all the forces acting on a body is zero, is it necessarily in equilibrium? If the sum of all the forces on a particle is zero, is it necessarily in equilibrium?

The earth moving round the sun in circular orbit is acted upon by a force and hence work must be done on the earth by the force. Explain.

A LASER is a source of very intense, monochromatic, and unidirectional beam of light. These properties of a laser light can be exploited to measure long distances. The distance of the Moon from the Earth has been already determined very precisely using a laser as a source of light. A laser light beamed at the Moon takes 2.56s to return after reflection at the Moon’s surface. How much is the radius of the lunar orbit around the Earth?

How is mean free path depends on number density of the gas?

When a dielectric slab is gradually inserted between the plates of an isolated parallel-plate capacitor, the energy of the system decreases. What can you conclude about the force on the slab exerted by the electric field?

The sign of work done by a force on a body is important to understand. State carefully if the following quantities are positive or negative:
Work done by gravitational force in the above case.

Does a solid also have two kinds of molar heat capacities C_P and C_v? If yes, do we have C_P > C_v? Is C_P - C_v = R?