Question

When orange light falls on a photo sensitive surface the photocurrent begins to flow.Velocity of emitted electrons will be more when surface is hit by

• A. Red light
• B. Violet light
• C. Thermal radiations
• D. Radio waves

Answer 1

Answer: (B)

Violet light

Frequency of Red light, thermal radiations and radio waves and less than frequency of orange light whereas frequency of violet light is more than frequency of orange light. So, violet light has more energy.

Since energy $=h\nu$

So, when violet light is hit on the surface velocity of emitted electrons will be more.