Charge and Current

Q.

Explain why a blackened platinum strip when placed at the radius of curvature turns red hot, only when the cathode taken has a concave shape.

Q.

State three factors on which the rate of emission of electrons from a metal surface depends.

Q.

An apparatus used for the measurement of quantity of electricity is known as a

[BHU 1979]

1. Calorimeter

2. Cathetometer

3. Coulometer

4. Colorimeter

Q.

Unit of Faraday is

1. Coulomb
2. Ampere

3. 

4. 

Q.

1. What is thermionic emission ?
2. Name the unit in which the work functions of a metal is expressed ?