A bird is in a wire cage hanging from a spring balance.Is the reading indicated on the balance,when the bird is flying out in the cage greater than ,less than or the same as that when the bird is sitting in the cage ?Explain.

When a ammeter is put in a circuit, does it read slightly less or more than the actual current in the original circuit? Explain.

When a voltemeter is put across a part of the circuit, does it read slightly less or more than the original voltage drop across the part? Explain.

When a body slides down from rest along a smooth inclined plane making anangle of 45^@ with the horizontal, it takes time T. when the same body slides down from rest along a rough inclined plane making the same angle and through the same distance, it is seen to take time pT, where p is some number greater than 1. Calculate the co-efficient of friction between the body and the rough plane.

A bird is tossing (flying to and fro 0 between two cars moving towards each other on a straight road. On car has a speed of 18 km /h while the other has the speed of 27 km /h. The bird starts moving from first caer towards the other and is moving with the speed of 36 km /h and when the two cars were separated by 36 km. What is the total distance comered by the bird ? What is the total displacement of the bird ?

In comparing the resistance of two cells P and Q with a sides wire bridge, a balance point is obtained when the sliding contact is 30 cm from the zero end of the wire. The resistances P and Q are interchanged and the balance is obtained at 120 cm from the same emf. Find the ratio of the resistance P and Q and the length of the bridge wire

Explain clearly, with examples, the distinction between :- magnitude of average velocity over an interval of time, and the average speed over the same interval. [Average speed of a particle over an interval of time is defined as the total path length divided by the time interval]. Show in both (a) and (b) that the second quantity is either greater than or equal to the first. When is the equality sign true ? [For simplicity, consider one-dimensional motion only].

A bird weights 2 kg and is inside a cage of 1 kg. If it starts flying then what is weight of bird and cage assembly?

In a meter bridge experiment null point is obtained at 20 cm. from one end of the wire when resistance X is balanced against another resistance Y. If XltY, then where will be the new position of the null point from the same end, if one deicdes to balance a resistance of 4 X against Y?

The two parallel circular loops of wire shown in fig each have a radius R = 20 cm and are separated by a distance a = 0.5 cm. The bottom loop is held fixed and the top loop hangs from one end of the arm of an equal arm balance. Since a is much smaller than R, the magnetic field produced by one loop at the other is practically the same as if both were long straight wires. if the current in each loop is 20 A. How much additional mass m must be added to the right-hand pan of the balance to keep the loops separated by 0.5 cm, when the currents are turned on?