Q. The de-Broglie wavelength of a ball of mass 120 g moving at a speed of 20 m/s is
A) 3.5$\times 10^{- 34}$ m
B) $2.8 \times 10^{- 34}$ m
C) $1.2 \times 10^{- 34}$ m
D) $2.1 \times 10^{- 34}$ m
Explanation
(b) de-Broglie wavelength, $\lambda = \frac{h}{mv}$
=$\frac{6.6 \times 10^{- 34}}{120 \times 10^{- 3} \times 20}$
=2.75$\times 10^{- 34}$ m
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.