Thermodynamics — Physics STD 11 Science — Question

In which of the following examples of motion, can the body be considered approximately a point object:
A spinning cricket ball that turns sharply on hitting the ground.

Two sound sources produce 20 beats in 5s. By how much do their frequencies differ?

What are the measures to reduce the effect of friction? Explain. Explain the usefulness of lubricants.

Consider a simple pendulum, having a bob attached to a string, that oscillates under the action of the force of gravity. Suppose that the period of oscillation of the simple pendulum depends on its length (l), mass of the bob (m) and acceleration due to gravity (g). Derive the expression for its time period using method of dimensions.

A conducting circular loop of radius a is connected to two Iong, straight wires. The straight wires carry current I as shown in figure. Find the magnetic field B at the centre of the loop.

Give the magnitude and direction of the net force acting on a stone of mass 0.1kg, (Neglect air resistance throughout.)
Just after it is dropped from the window of a train accelerating with 1ms^-2.

Write an expression for the moment of inertia of a ring of mass M and radius r.

1. About an axis passing through its centre and perpendicular to its plane.
2. About its diameter.
3. About a tangent in its own plane.
4. About a tangent perpendicular to the plane of the ring.

Calculate the heat absorbed by a system in going through the cyclic process shown in figure.