Question

Which of the following statements is correct about photoelectric effect?
A. The number of electrons ejected from metal surface is inversely proportional to intensity of light
B. Below threshold frequency, photoelectric effect can be observed
C. At higher frequency than threshold frequency, the ejected electrons have certain kinetic energy
D. At higher frequency than threshold frequency, the electron is still on the metal surface

• A. A
• B. B
• C. C
• D. D

Answer 1

Answer: (C)

Kinetic energy of photoelectrons
$KE=hv-h{v}_0$
$\Rightarrow \text{ When }v>v_0,KE>0$
So, statement 3 is correct.
where, $v=$ frequency of incident light
$v_0=$ threshold frequency
Now, other options will be correct when
1. Number of photoelectrons ejected from metal surface intensity of light.
2. When, $\$v4$. When, $v=v_0,KE=0$ the electrons will be still on the metal surface.