Browse by Stream
QnA
Home
QnA
Go To Your Study Dashboard

Get Answers to all your Questions

header-bg qa
  • Home
  • NCERT
  • The mass of an electron is 9.1 x 10 ^-31 kg If its K.E. is 3.0 x 10^-25 J, calculate its wavelength.

2.21 The mass of an electron is 9.1\times 10^{-31}\ \textup{kg} If its K.E. is 3.0\times 10^{-25}\ \textup{J}, calculate its wavelength.

Answers (2)

best_answer

The wavelength of an electron can be found by de Broglie's equation:

\lambda = \frac{h}{mv}

Given the K.E. of electron 3.0\times 10^{-25}\ \textup{J} which is equal to \frac{1}{2}mv^2.

Hence we get, 

\frac{1}{2}mv^2 = 3.0\times10^{-25}J

v = \sqrt{\frac{2KE}{m}} = \sqrt{\frac{2(3.0\times10^{-25}J)}{9.1\times10^{-31}kg}} = 811.579\ m/s

Hence the wavelength is given by,

\lambda = \frac{6.626\times10^{-34}Js}{(9.1\times10^{-31}kg)(811.579\ m/s)}

= 8.9625\times10^{-7}m

Posted by

Divya Prakash Singh

View full answer

Crack CUET with india's "Best Teachers"

  • HD Video Lectures
  • Unlimited Mock Tests
  • Faculty Support
cuet_ads

896.7 nm

Posted by

Krishna shinde

View full answer

Similar Questions

Trending Articles/News

anam-khan

CBSE Board Exams 2025: Counselling for students, parents from February 1
anam-khan

CBSE asks schools to include APAAR IDs in school ID after NTA says ‘not mandatory’ for NEET
anam-khan

CBSE Board Exams 2025: What the ethics code bans from exam centres

Latest Question