MCQ
The mass of a photon with a wavelength equal to $1.54 \times {10^{ - 8}}\,cm$ is
- A$0.8268 \times {10^{ - 34}}\,kg$
- B$1.2876 \times {10^{ - 33}}\,kg$
- ✓$1.4285 \times {10^{ - 32}}\,kg$
- D$1.8884 \times {10^{ - 32}}\,kg$
✓
Answer
Correct option: C.
$1.4285 \times {10^{ - 32}}\,kg$
c
(c) We know that $\lambda = \frac{h}{{mv}}$ ; $\therefore $ $m = \frac{h}{{m\lambda }}$
(c) We know that $\lambda = \frac{h}{{mv}}$ ; $\therefore $ $m = \frac{h}{{m\lambda }}$
The velocity of photon $(v)$ = $3 \times {10^8}\,m\,{\sec ^{ - 1}}$
$\lambda = 1.54 \times {10^{ - 8}}\,cm = 1.54 \times {10^{ - 10}}\,meter$
$\therefore $ $m = \frac{{6.626 \times {{10}^{ - 34}}\,Js}}{{1.54 \times {{10}^{ - 10}}\,m \times 3 \times {{10}^8}\,m\,{{\sec }^{ - 1}}}}$
$ = \,1.4285 \times {10^{ - 32}}\,kg$.
Need a full question paper?
Generate a complete, print-ready paper with questions like this in minutes — across 16+ boards, with answer keys.
Explore more
Similar questions
"An acid is a substance that is capable of donating a hydrogen ion $H^+$ and bases are substances capable of accepting a hydrogen ion, $H^+$". The above statement is justified by
→In reaction $2 MnO _4^{-}+3 H _2 O _2 \longrightarrow 2 MnO _2+3 O _2+$ $2 OH ^{-}+x$, the $x$ is :
→A metal surface is exposed to $500\, \mathrm{~nm}$ radiation. The threshold frequency of the metal for photoelectric current is $4.3 \times 10^{14}\, \mathrm{~Hz}$. The velocity of ejected electron is $.......\,\times 10^{5} \mathrm{~ms}^{-1}$ (Nearest integer)
→[Use : $\left.\mathrm{h}=6.63 \times 10^{-34}\, \mathrm{Js}, \mathrm{m}_{\mathrm{e}}=9.0 \times 10^{-31}\, \mathrm{~kg}\right]$
The $100^{th}$ element is named in honor of :
→Which of the following is not correctly matched
In the formation of a molecule by an atom
The $H-C-H$ bond angle in $CH_4$ is $109.5^o$, due to lone pair repulsion, the $H - O - H$ angle in $H_2O$ will
→Given that the dissociation constant for ${H_2}O$ is ${K_w} = 1 \times {10^{ - 14}}$ $mol{e^2}\,\,litr{e^{ - 2}},$ what is the $HCl$ of a $0.001\,\,molar\,\,KOH$ solution
→For a reversible reaction, the rate constants for the forward and backward reactions are $2.38\times10^{-4}$ and $8.15\times10^{-5}$ respectively. The equilibrium constant for the reaction is
→$(A)$ ના દ્વિબંધ સમકક્ષ કેટલા છે ?
→