Dual Nature Of Light Question 141
Question: The de-Broglie wavelength of a particle moving with a velocity 2.25 ´ 108 m/s is equal to the wavelength of photon. The ratio of kinetic energy of the particle to the energy of the photon is (velocity of light is 3 ´ 108 m/s) [EAMCET (Med.) 2003]
Options:
A) 1/8
B) 3/8
C) 5/8
D) 7/8
Show Answer
Answer:
Correct Answer: B
Solution:
$ {K_{particle}}=\frac{1}{2}mv^{2} $ also $ \lambda =\frac{h}{mv} $
$ \Rightarrow {K_{particle}}=\frac{1}{2}( \frac{h}{\lambda v} ),.,v^{2}=\frac{vh}{2\lambda } $ …(i) $ {K_{photon}}=\frac{hc}{\lambda } $ …(ii)
$ \therefore ,\frac{{K_{particle}}}{{K_{photon}}}=\frac{v}{2c}=\frac{2.25\times 10^{8}}{2\times 3\times 10^{8}}=\frac{3}{8} $
BETA
