A brass ball is tied to a thin wire and swung, so as to move uniformly in a horizontal circle. Which of the following statement(s) in this regard is/are true?

1. The ball moves with constant velocity.

2. The ball moves with constant speed.

3. The ball moves with constant acceleration.

4. The magnitude of the acceleration of the ball is constant.

Select the correct answer using the codes given below.

Two long wires each carrying a DC current in the same direction are placed close to each other.

Which one of the following statement is correct?

The absolute zero, i.e. temperature below which is not achievable, is about

Lightning conductors are used to protect building from lightning strikes. Which of the following statement(s) is/are true about lightning conductors?

1. Lightning conductors create an electric field at its top, so that lightning strikes it preferentially.

2. Lightning conductors reduce the effect of the strike by uniformly distributing the charge (current) over the surface of the building.

3. Lightning conductors take all charges (current) to deep down in the earth.

4. Lightning conductors must be installed at a place taller than the building.

Select the correct answer using the codes given below