JEE Main 2021 · PhysicsNumerical answerNumerical valueMediumCalculation

JEE Main 26 February 2021, Shift 2, Physics Q24

Question 24 of 90 in this shift, Physics question 24 of 30, Section B.

Two stream of photons, possessing energies equal to twice and ten times the work function of metal are incident on the metal surface successively. The value of ratio of maximum velocities of the photoelectrons emitted in the two respective cases is

x : y

. The value of

x

is ________.

Official answer

NTA final key.

Chapter: Dual Nature of Radiation and Matter
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.