Dual Nature Of Radiation And Matter Ques 79
79. The threshold frequency for photoelectric effect on sodium corresponds to a wavelength of $5000 $ $\AA$. Its work function is
[1988]
(a) $4 \times 10^{-19}$ $ J$
(b) $1$ $ J$
(c) $2 \times 10^{-19}$ $ J$
(d) $3 \times 10^{-19}$ $ J$
Show Answer
Answer:
Correct Answer: 79.(a)
Solution:
- (a) $W_0=\frac{h c}{\lambda_0}$
$ =\frac{6.63 \times 10^{-34} \times 3 \times 10^{8}}{5000 \times 10^{-10}}=4 \times 10^{-19} $ $J $
BETA
