JEE Main 2021 · PhysicsMultiple choiceSingle correctEasyCalculation

JEE Main 25 July 2021, Shift 2, Physics Q19

Question 19 of 90 in this shift, Physics question 19 of 30, Section A.

An electron moving with speed

v

and a photon moving with speed

c

, have same D-Broglie wavelength. The ratio of kinetic energy of electron to that of photon is :

(1) $\frac{2c}{v}$
(2) $\frac{v}{2c}$ Official answer
(3) $\frac{3c}{v}$
(4) $\frac{v}{3c}$

Official answer

Option 2

NTA final key.

Chapter: Dual Nature of Radiation and Matter
Topic: Matter Waves
Idea tested: Electron vs Photon (Same Wavelength)

Same idea in other shifts

Asked 3× in all

29 Jan 2024, Shift 1 · Q46The de-Broglie wavelength of an electron is the same as that of a photon. If velocity of electron is 25% of the velocity of light, then…MediumSingle correct
26 Jun 2022, Shift 1 · Q47An electron with speed $v$ and a photon with speed c have the same de-Broglie wavelength. If the kinetic energy and momentum of electron…MediumSingle correct

Question text from the official JEE Main paper published by NTA; answer from the final answer key. Chapter, topic and idea tags, difficulty and skill are Lumi’s. Lumi analyses 108 of the 174 JEE Main shifts held from 2017 to 2026.