Q18.When photon of energy 4.0eV strikes the surface of a metal A, the ejected photoelectrons have maximum kinetic energy TAeV and de-Broglie wavelength λA. The maximum kinetic energy of photoelectrons liberated from another metal B by photon of energy 4.50eV is TB = (TA −1.5)eV. If the de-Broglie wavelength of these photoelectrons λB = 2λA, then the work function of metal B is: (1) 4eV (2) 2eV (3) 1.5eV (4) 3eV
What This Question Tests
This problem combines the photoelectric effect with the de-Broglie wavelength concept, requiring setting up and solving equations for kinetic energy and wavelength for two different metals.
Concepts Tested
Formulas Used
KE_max = hν - Φ
λ = h/√(2mKE_max)
📚 NCERT Sections This Tests
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?
11.8 — Light Of Frequency 7.21 × 1014 Hz Is Incident On A Metal Surface.
Physics Class 12 · Chapter 11
11.8 Light of frequency 7.21 × 1014 Hz is incident on a metal surface. Electrons with a maximum speed of 6.0 × 105 m/s are ejected from the surface. What is the threshold frequency for photoemission of electrons?
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?
📋 Question Details
- Chapter
- Dual Nature of Matter
- Topic
- Photoelectric effect, de-Broglie wavelength
- Year
- 2020
- Shift
- 08 Jan Shift 1
- Q Number
- Q18
- Type
- MCQ
- NCERT Ref
- Class 12 Physics Ch 11: Dual Nature of Radiation and Matter
More from this Chapter
Q68.Sodium and copper have work functions 2.3eV and 4.5eV respectively. Then the ratio of the wave lengths is nearest to JEE Main 2002 JEE Main Previous Year Paper (1) 1 : 2 (2) 4 : 1 (3) 2 : 1 (4) 1 : 4
Q69.Formation of covalent bonds in compounds exhibits (1) wave nature of electron (2) particle nature of electron (3) both wave and particle nature of electron (4) none of these
Q80.Uncertainity in position of a minute particle of mass 25 g in space is 10−5 m. What is the uncertainity in its velocity (in ms−1)? ( h = 6.6 × 10−34Js) (1) 2.1 × 10−34 (2) 0.5 × 10−34 (3) 2.1 × 10−28 (4) 0.5 × 10−23 Q81. β - particle is emitted in radioactivity by (1) conversion of proton to neutron (2) from outermost orbit (3) conversion of neutron to proton (4) β-particle is not emitted
Q27.The earth radiates in the infra-red region of the spectrum. The spectrum is correctly given by (1) Rayleigh Jeans law (2) Planck's law of radiation (3) Stefan's law of radiation (4) Wien's law