Question: What is the threshold frequency in the photoelectric effect?

Options:

1. The minimum frequency required to eject an electron from a metal surface
2. The maximum frequency that can cause photoemission
3. The frequency at which light is absorbed by a metal
4. The frequency of the emitted electrons

Correct Answer: The minimum frequency required to eject an electron from a metal surface

Solution:

The threshold frequency is the minimum frequency of incident light required to eject electrons from a metal surface.