LIVE Course for free

Rated by 1 million+ students
Get app now
0 votes
in Physics by (54.3k points)
closed by
If the kinetic energy of an electron gets doubled, its de Broglie wavelength will become _________.
1. doubled
2. (1/√2) times
3. squared
4. √2 times

1 Answer

0 votes
by (30.0k points)
selected by
Best answer
Correct Answer - Option 2 : (1/√2) times


  • de Broglie wavelength of electrons: Louis de Broglie theorized that not only light possesses both wave and particle properties, but rather particles with mass - such as electrons - do as well.
    • The wavelength of material waves is also known as the de Broglie wavelength.
  • de Broglie wavelength (λ) of electrons can be calculated from Planks constant h divided by the momentum of the particle.

λ = h/p

where λ is de Broglie wavelength, h is Plank's const, and p is the momentum.

  • In terms of Energy, de Broglie wavelength of electrons:


where λ is de Broglie wavelength, h is Plank's const, m is the mass of an electron, and E is the energy of the electron.


Given that E2 = 2E1

\(λ_1=\frac{h}{\sqrt{2mE_1}}\)       .....(i)

\(λ_2=\frac{h}{\sqrt{2mE_2}}\)       .....(ii)




So the correct answer is option 2.

Welcome to Sarthaks eConnect: A unique platform where students can interact with teachers/experts/students to get solutions to their queries. Students (upto class 10+2) preparing for All Government Exams, CBSE Board Exam, ICSE Board Exam, State Board Exam, JEE (Mains+Advance) and NEET can ask questions from any subject and get quick answers by subject teachers/ experts/mentors/students.