JEE PYQ: Atomic Physics Question 26
Question 26 - 2020 (02 Sep Shift 2)
A particle is moving 5 times as fast as an electron. The ratio of the de-Broglie wavelength of the particle to that of the electron is $1.878 \times 10^{-4}$. The mass of the particle is close to:
(1) $4.8 \times 10^{-27}$ kg
(2) $9.1 \times 10^{-31}$ kg
(3) $1.2 \times 10^{-28}$ kg
(4) $9.7 \times 10^{-28}$ kg
Show Answer
Answer: (4)
Solution
De Broglie wavelength $\lambda = \frac{h}{mv}$. $m \propto \frac{1}{\lambda v}$. $\frac{m’}{m} = \frac{v\lambda}{v’\lambda’} = \frac{1}{5} \times \frac{1}{1.878 \times 10^{-4}}$. $m = 9.7 \times 10^{-28}$ kg.
BETA
