Q. Calculate the velocity of an electron having wavelength of 0.15 nm Mass of an electron is $9.109 \times 10^{- 28}$g. ($h = 6.626 \times 10^{- 27}$erg-s).
A) $0.262 \times 10^{- 8}cm.s^{- 1}$
B) $2.062 \times 10^{- 15}cm.s^{- 1}$
C) $4.84 \times 10^{8}cm.s^{- 1}$
D) $2.062 \times 10^{- 9}cm.s^{- 1}$
Explanation
(c)
$\lambda = \frac{h}{mv}$
$v = \frac{h}{m\lambda} = \frac{6.626 \times 10^{- 27}}{9.109 \times 10^{- 28} \times 0.15 \times 10^{- 7}} = 4.84 \times 10^{8}cms^{- 1}$
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.