Saturation Current

Q.

Photo cells are used for the

1. Reproduction of sound from the cinema film

2. (b) and (c) both

3. Automatic switching of street light

4. Reproduction of pictures from the cinema film

Q. In a photoelectric experiment, if the intensity of incident light increases, the saturation current increases.

1. False
2. True

Q.

Alright. We have understood that there will be some photocurrent even when the potential maintained between the plates is zero. But is saturation current achieved at V = 0?

1. Yes, but only if the intensity is high and a lot of electrons are getting ejected.

2. Yes, always

3. No, never

Q.

Why don't we get maximum current (saturation current) at 0 potential

1. If we increase the potential of the plate the number of electron coming out also increases as the field from the collector plate is also aiding in the ejection of electrons.

2. The space near the emitter plate is full of freshly ejected slow moving electrons which restrict new low energy electrons from coming out.

3. At 0 potential the energy of the electrons is very less so they take long time to reach the other plate hence the low current.

4. Scientist are still trying to figure that out.

Q.

Photo cells are used for the

1. Reproduction of pictures from the cinema film

2. Reproduction of sound from the cinema film

3. Automatic switching of street light

4. (b) and (c) both