JEE Main 2026 · PhysicsMultiple choiceSingle correctEasyCalculation

JEE Main 5 April 2026, Shift 2, Physics Q43

Question 43 of 75 in this shift, Physics question 18 of 25, Section A.

An electron is travelling with a velocity

v

in free space and when it enters a medium, its velocity is reduced by 20%. The de Broglie wavelength of electron in the medium is

\alpha\lambda_0

, where

\lambda_0

is its de Broglie wavelength in free space. The value of

\alpha

is __________.

(1) $1.20$
(2) $1.0$
(3) $1.25$ Official answer
(4) $0.75$

Official answer

Option 3

NTA final key.

Chapter: Dual Nature of Radiation and Matter
Topic: Matter Waves
Idea tested: Basic Wavelength-Momentum Relation

Same topic in other shifts

All Matter Waves questions

4 Apr 2026, Shift 2 · Q44The de Broglie wavelength associated with an electron accelerated through a potential difference V is $\lambda_e$ and the de Broglie…EasySingle correct
5 Apr 2026, Shift 1 · Q35An electron of mass $m$ is moving in an electric field $\vec{E} = -2E_0\hat{i}$ ( $E_0$ = constant $> 0$ ), with an initial velocity…MediumSingle correct
6 Apr 2026, Shift 2 · Q47The de Broglie wavelength for an electron accelerated through the potential difference of $V_1$ volt is $\lambda_1$ . When the potential…EasyNumerical value
2 Apr 2025, Shift 2 · Q33An electron with mass $m$ with an initial velocity $(t=0)$ $\vec{v} = v_0\hat{i}$ $(v_0 > 0)$ enters a magnetic field…MediumSingle correct
7 Apr 2025, Shift 2 · Q43A photoemissive substance is illuminated with a radiation of wavelength $\lambda_i$ so that it releases electrons with de-Broglie…MediumSingle correct
8 Apr 2025, Shift 2 · Q50An electron is released from rest near an infinite non-conducting sheet of uniform charge density ' $-\sigma$ ' .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.