JEE PYQ: Atomic Structure Question 30
Question 30 - 2019 (08 Apr Shift 2)
If $p$ is the momentum of the fastest electron ejected from a metal surface after irradiation of light having wavelength $\lambda$, then for 1.5$p$ momentum, the wavelength should be: (KE » work function)
(1). ($\frac{3}{4}\lambda$)
(2). ($\frac{1}{2}\lambda$)
(3). ($\frac{2}{3}\lambda$)
(4). ($\frac{4}{9}\lambda$)
Show Answer
Answer: (4)
Solution
$\frac{hc}{\lambda} \approx \frac{p^2}{2m}$. New: $\frac{hc}{\lambda_1} = \frac{(1.5p)^2}{2m}$. $\lambda_1 = \frac{4}{9}\lambda$.
BETA
