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Friday, 9 October

JEE Main 2026 · PhysicsMultiple choiceSingle correctMediumMulti-step

JEE Main 5 April 2026, Shift 1, Physics Q35

Question 35 of 75 in this shift, Physics question 10 of 25, Section A.

An electron of mass mm is moving in an electric field E⃗=−2E0i^\vec{E} = -2E_0\hat{i} (E0E_0 = constant >0> 0), with an initial velocity V⃗=v0i^\vec{V} = v_0\hat{i} (v0v_0 = constant >0> 0). If λ0=h4mv0\lambda_0 = \frac{h}{4mv_0}, its de Broglie wavelength at time tt is ________. (ee = charge of electron)
  1. (1)4λ0[1−E0e2mtv0]\frac{4\lambda_0}{\left[1 - \frac{E_0 e}{2m}\frac{t}{v_0}\right]}
  2. (2)4λ0[1+E0e2mtv0]\frac{4\lambda_0}{\left[1 + \frac{E_0 e}{2m}\frac{t}{v_0}\right]}
  3. (3)4λ0[1+2E0emtv0]\frac{4\lambda_0}{\left[1 + \frac{2E_0 e}{m}\frac{t}{v_0}\right]}Official answer
  4. (4)4λ0[1−2E0emtv0]\frac{4\lambda_0}{\left[1 - \frac{2E_0 e}{m}\frac{t}{v_0}\right]}

Official answer

Option 3

NTA final key.

Chapter
Dual Nature of Radiation and Matter
Topic
Matter Waves
Idea tested
Wavelength in E-Field as Function of Time

Same topic in other shifts

All Matter Waves questions
  1. 4 Apr 2026, Shift 2 · Q44The de Broglie wavelength associated with an electron accelerated through a potential difference V is λe\lambda_e and the de Broglie…EasySingle correct
  2. 5 Apr 2026, Shift 2 · Q43An electron is travelling with a velocity vv in free space and when it enters a medium, its velocity is reduced by 20%. The de Broglie…EasySingle correct
  3. 6 Apr 2026, Shift 2 · Q47The de Broglie wavelength for an electron accelerated through the potential difference of V1V_1 volt is λ1\lambda_1. When the potential…EasyNumerical value
  4. 2 Apr 2025, Shift 2 · Q33An electron with mass mm with an initial velocity (t=0)(t=0) v⃗=v0i^\vec{v} = v_0\hat{i} (v0>0)(v_0 > 0) enters a magnetic field…MediumSingle correct
  5. 7 Apr 2025, Shift 2 · Q43A photoemissive substance is illuminated with a radiation of wavelength λi\lambda_i so that it releases electrons with de-Broglie…MediumSingle correct
  6. 8 Apr 2025, Shift 2 · Q50An electron is released from rest near an infinite non-conducting sheet of uniform charge density '−σ-\sigma' .The rate of change of…MediumNumerical value

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 42 of the 174 JEE Main shifts held from 2017 to 2026.