JEE Main 2021 · PhysicsMultiple choiceSingle correctEasyCalculation

JEE Main 26 August 2021, Shift 1, Physics Q7

Question 7 of 90 in this shift, Physics question 7 of 30, Section A.

In a photoelectric experiment ultraviolet light of wavelength 280 nm is used with lithium cathode having work function

\phi=2.5

eV. If the wavelength of incident light is switched to 400 nm, find out the change in the stopping potential. (

h=6.63\times10^{-34}

Js,

c=3\times10^{8}\ \mathrm{ms^{-1}}

)

(1)1.3 VOfficial answer
(2)1.9 V
(3)0.6 V
(4)1.1 V

Official answer

Option 1

NTA final key.

Chapter: Dual Nature of Radiation and Matter
Topic: Photoelectric Effect
Idea tested: Stopping Potential

Same idea in other shifts

Asked 4× in all

5 Apr 2024, Shift 2 · Q47Which of the following statement is not true about stopping potential ( $V_0$ ) ?EasySingle correct
6 Apr 2024, Shift 2 · Q47When UV light of wavelength 300 nm is incident on the metal surface having work function 2.13 eV, electron emission takes place. The…EasySingle correct
27 Aug 2021, Shift 2 · Q19A monochromatic neon lamp with wavelength of 670.5 nm illuminates a photo-sensitive material which has a stopping voltage of 0.48 V. What…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.