Q31.What is the work function of the metal if the light of wavelength 4000 A generates photoelectrons of velocity 6 × 105 ms−1 from it? (Mass of electron = 9 × 10−31 kg, velocity of light = 3 × 108 ms−1 , Planck's constant = 6 .626 ×10−34 Js, Charge of electron = 6 .626 ×10−34 Js) (1) 0 .9 eV (2) 4 .0 eV (3) 3 .1 eV (4) 2 .1 eV
What This Question Tests
This question tests the application of Einstein's photoelectric equation to calculate the work function, given the incident light's wavelength and the photoelectron's velocity, requiring unit conversions.
Concepts Tested
Formulas Used
E = hc/λ
KE = 1/2 mv²
E = W + KE
1 eV = 1.602 × 10⁻¹⁹ J
📚 NCERT Sections This Tests
11.2 — The Work Function Of Caesium Metal Is 2.14 Ev. When Light Of
Physics Class 12 · Chapter 11
11.2 The work function of caesium metal is 2.14 eV. When light of frequency 6 ×1014Hz is incident on the metal surface, photoemission of electrons occurs. What is the (a) maximum kinetic energy of the emitted electrons, (b) Stopping potential, and (c) maximum speed of the emitted photoelectrons?
11.7 — The Work Function For A Certain Metal Is 4.2 Ev. Will This Metal Give
Physics Class 12 · Chapter 11
11.7 The work function for a certain metal is 4.2 eV. Will this metal give hotoelectric emission for incident radiation of wavelength 330 nm?
11.3 — The Photoelectric Cut-Off Voltage In A Certain Experiment Is 1.5 V.
Physics Class 12 · Chapter 11
11.3 The photoelectric cut-off voltage in a certain experiment is 1.5 V. What is the maximum kinetic energy of photoelectrons emitted?
📋 Question Details
- Chapter
- Atomic Structure
- Topic
- Photoelectric effect
- Year
- 2019
- Shift
- 12 Jan Shift 1
- Q Number
- Q31
- Type
- MCQ
- NCERT Ref
- Class 11 Chemistry Ch 2: Structure of Atom
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