JEE Main 2021 · PhysicsMultiple choiceSingle correctMediumCalculation

JEE Main 26 August 2021, Shift 2, Physics Q8

Question 8 of 90 in this shift, Physics question 8 of 30, Section A.

The de-Broglie wavelength of a particle having kinetic energy E is

\lambda

. How much extra energy must be given to this particle so that the de-Broglie wavelength reduces to 75% of the initial value ?

(1)E
(2) $\frac{1}{9}$ E
(3) $\frac{7}{9}$ EOfficial answer
(4) $\frac{16}{9}$ E

Official answer

Option 3

NTA final key.

Chapter: Dual Nature of Radiation and Matter
Topic: Matter Waves
Idea tested: Wavelength from Kinetic Energy

Same idea in other shifts

Asked 7× in all

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9 Apr 2024, Shift 1 · Q46A proton, an electron and an alpha particle have the same energies. Their de-Broglie wavelengths will be compared as :EasySingle correct
6 Apr 2023, Shift 1 · Q35The kinetic energy of an electron, $\alpha$ -particle and a proton are given as 4 K, 2 K and K respectively. The de-Broglie wavelength…MediumSingle correct
15 Apr 2023, Shift 1 · Q45The de Broglie wavelength of an electron having kinetic energy E is $\lambda$ . If the kinetic energy of electron becomes $\frac{E}{4}$ ,…EasySingle correct
25 Jul 2021, Shift 1 · Q6What should be the order of arrangement of de-Broglie wavelength of electron ( $\lambda_e$ ), an $\alpha$ -particle ( $\lambda_\alpha$ ) and…EasySingle correct
9 Jan 2020, Shift 1 · Q17A particle moving with kinetic energy E has de Broglie wavelength $\lambda$ . If energy $\Delta E$ is added to its energy, the wavelength…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.