Q53.When light of wavelength 248 nm falls on a metal of threshold energy 3. 0 eV , the de-Broglie wavelength of o emitted electrons is ________ A . (Round off to the Nearest Integer). [Use : √3 = 1. 73, h = 6. 63 × 10−34 Js; me = 9. 1 × 10−31 kg; c = 3. 0 × 108 ms−1; 1 eV = 1. 6 × 10−19 J]
What This Question Tests
This problem integrates concepts from the photoelectric effect to calculate the kinetic energy of emitted electrons and then uses the de Broglie hypothesis to determine their wavelength, requiring careful unit conversions.
Concepts Tested
Formulas Used
E = hc/λ
E = W₀ + K.E.
K.E. = 1/2 mv²
λ_dB = h/mv
📚 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.
11.8 — 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?
11.3 — 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 and de Broglie Wavelength
- Year
- 2021
- Shift
- 16 Mar Shift 1
- Q Number
- Q53
- Type
- Multi concept
- NCERT Ref
- Class 11 Chemistry Ch 2: Atomic Structure
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