Question

The photoelectric emission from a surface starts only when the light incident upon the surface of metal has certain minimum:

• A. intensity
• B. wavelength
• C. frequency
• D. velocity

Answer 1

Answer: (C)

frequency

The minimum frequency required for the emission of electrons is called threshold frequency below which no photoelectron is emitted. This is denoted by ${\nu }_o$.

The minimum energy required for the emission of photoelectrons from metal is called work function of that metal $W$.
$W=h{\nu }_o$