Q23.Radiation of wavelength λ is incident on a photocell. The fastest emitted photoelectron has a speed v . If the 3λ wavelength is changed to , the speed of the fastest emitted photoelectron will be 4 4 2 (1) = v( 1 1 3 ) 2 (2) = v( 34 ) 2 (3) > v( 3 1 1 4 ) 2 (4) < v( 43 )
What This Question Tests
The question applies Einstein's photoelectric equation to relate the wavelength of incident radiation, work function, and the maximum kinetic energy (and thus speed) of emitted photoelectrons for two different wavelengths.
Concepts Tested
Formulas Used
E = hc/λ
KE_max = E - Φ
KE_max = ½mv²
📚 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?
11.6 — 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.
📋 Question Details
- Chapter
- Dual Nature of Matter
- Topic
- Photoelectric effect
- Year
- 2016
- Shift
- 03 Apr
- Q Number
- Q23
- Type
- MCQ
- NCERT Ref
- Class 12 Physics Ch 11: Dual Nature of Radiation and Matter
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