Q25.When radiation of wavelength A is used to illuminate a metallic surface, the stopping potential is V . When the same surface is illuminated with radiation of wavelength 3A , the stopping potential is V4 . If the threshold wavelength for the metallic surface is nλ then value of n will be :
What This Question Tests
This question tests the application of Einstein's photoelectric equation to two different wavelengths, relating stopping potential and wavelength to determine the threshold wavelength for the metallic surface.
Concepts Tested
Formulas Used
eV_s = hc/λ - Φ
Φ = hc/λ_th
📚 NCERT Sections This Tests
11.6 — The Threshold Frequency For A Certain Metal Is 3.3 × 1014 Hz. If Light
Physics Class 12 · Chapter 11
11.6 The threshold frequency for a certain metal is 3.3 × 1014 Hz. If light of frequency 8.2 × 1014 Hz is incident on the metal, predict the cut- off voltage for the photoelectric emission.
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?
📋 Question Details
- Chapter
- Dual Nature of Matter
- Topic
- Photoelectric effect
- Year
- 2020
- Shift
- 02 Sep Shift 1
- Q Number
- Q25
- Type
- Numerical
- NCERT Ref
- Class 12 Physics Ch 11: Dual Nature of Radiation and Matter
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