Q27.A certain metallic surface is illuminated by monochromatic radiation of wavelength λ . The stopping potential for photoelectric current for this radiation is 3 V 0. If the same surface is illuminated with a radiation of wavelength 2λ, the stopping potential is V0. The threshold wavelength of this surface for photoelectric effect is___________ λ.
What This Question Tests
This question requires applying Einstein's photoelectric equation to two different wavelengths and stopping potentials to determine the threshold wavelength of the surface.
Concepts Tested
Formulas Used
eV_s = hc/λ - φ
φ = hc/λ_threshold
📚 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
- 2021
- Shift
- 20 Jul Shift 2
- Q Number
- Q27
- Type
- Numerical
- NCERT Ref
- Class 12 Physics Ch 11: Dual Nature of Matter
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