Learn

Saturday, 31 October

JEE Main 2022 · PhysicsMultiple choiceSingle correctMediumMulti-step

JEE Main 26 June 2022, Shift 1, Physics Q47

Question 47 of 90 in this shift, Physics question 17 of 30, Section A.

An electron with speed vv and a photon with speed c have the same de-Broglie wavelength. If the kinetic energy and momentum of electron are EeE_e and pep_e and that of photon are EphE_{ph} and pphp_{ph} respectively. Which of the following is correct ?
  1. (1)EeEph=2cv\frac{E_e}{E_{ph}}=\frac{2c}{v}
  2. (2)EeEph=v2c\frac{E_e}{E_{ph}}=\frac{v}{2c}Official answer
  3. (3)pepph=2cv\frac{p_e}{p_{ph}}=\frac{2c}{v}
  4. (4)pepph=v2c\frac{p_e}{p_{ph}}=\frac{v}{2c}

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
  1. 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
  2. 25 Jul 2021, Shift 2 · Q19An electron moving with speed vv and a photon moving with speed cc, have same D-Broglie wavelength. The ratio of kinetic energy of…EasySingle 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.