NEETPhysicsDual Nature of Radiation and MatterMCQ+4 / −1
Monochromatic radiation emitted when electron on hydrogen atom jumps from first excited to the ground state irradiates a photosensitive material. The stopping potential is measured to be 3.57 V. The threshold frequency of the material is
- A4 1015 Hz
- B5 1015 Hz
- C1.6 1015 Hz
- D2.5 1015 Hz
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Correct answer: C
Energy released from first exited state to the
ground state :
E = (– 3.4) – (– 13.6) = 10.2 eV
Work function = E – 3.75 eV = (10.2 – 3.75) eV
= 6.63 eV
h = 6.63
= = 1.6 1015 Hz
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