EMF of a cell is dependent on

1. the shape of electrodes
2. the material of electrodes
3. the distance between the electrodes
4. Both (a) and (b)

An object is vibrating at 4000 Hz. The time period of sound produced is

1. 0.0025 s
2. 0.025 s
3. 0.00025 s
4. 0.005 s

If a man is travelling in a car in a straight line path and the car suddenly turns right, then the man experiences a severe push towards the left. Explain.