Question

1. According to energy gap, Classify them as metal, Insulator, and semiconductor.

2. From which of the above material we can eject electrons with minimum effort Explain

3. In Photo electric effect, while we are measuring photo current by varying retarding potential the variations is as shown in graph.

Answer 1

1. Insulator, semiconductor, and conductor 

2. Metals 

3. This graph shows that photo current increases and reaches saturation with anode potential. This increase in current shows that electrons are emitted from the metal surface with different energies.