JEE Main 2021 · ChemistryNumerical answerNumerical valueEasyCalculation

JEE Main 26 August 2021, Shift 2, Chemistry Q52

Question 52 of 90 in this shift, Chemistry question 22 of 30, Section B.

A metal surface is exposed to 500 nm radiation. The threshold frequency of the metal for photoelectric current is

4.3 \times 10^{14}

Hz. The velocity of ejected electron is __________

\times 10^5

\mathrm{ms^{-1}}

. (Nearest integer) [Use : h =

6.63 \times 10^{-34}

Js,

\mathrm{m_e}

9.0 \times 10^{-31}

kg]

Official answer

NTA final key.

Chapter: Structure of Atom
Topic: Photoelectric Effect
Idea tested: Einstein's Photoelectric Equation

Same idea in other shifts

Asked 14× in all

5 Apr 2026, Shift 1 · Q41Light source having wavelength 331 nm is used to generate photo-electrons whose stopping potential is 0.2 V. The work function of the used…EasySingle correct
4 Apr 2024, Shift 2 · Q47Given below are two statements: one is labelled as Assertion A and the other is labelled as Reason R. Assertion A: Number of photons…MediumAssertion–reason
6 Apr 2024, Shift 1 · Q47In photoelectric experiment energy of 2.48 eV irradiates a photo sensitive material. The stopping potential was measured to be 0.5 V. Work…EasySingle correct
9 Apr 2024, Shift 2 · Q47UV light of $4.13$ eV is incident on a photosensitive metal surface having work function $3.13$ eV. The maximum kinetic energy of ejected…EasySingle correct
28 Jul 2022, Shift 2 · Q17Two streams of photons, possessing energies equal to five and ten times the work function of metal are incident on the metal surface…EasySingle correct
29 Jul 2022, Shift 1 · Q46The kinetic energy of emitted electron is E when the light incident on the metal has wavelength $\lambda$ . To double the kinetic energy,…MediumSingle correct
24 Jun 2022, Shift 1 · Q56When light of frequency twice the threshold frequency is incident on the metal plate, the maximum velocity of emitted electron is $v_1$ .…MediumNumerical value
28 Jun 2022, Shift 2 · Q47Let $K_1$ and $K_2$ be the maximum kinetic energies of photo-electrons emitted when two monochromatic beams of wavelength $\lambda_1$ and…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.