Dual Nature of Radiation and Matter - Result Question 31
33. 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 materials is :
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======= ####33. 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 materials is :
c3eec34ec6b1fad69db54a20ad4b2dca40c2aa54 (a) $4 \times 10^{15} Hz$
(b) $5 \times 10^{15} Hz$
(c) $1.6 \times 10^{15} Hz$
(d) $2.5 \times 10^{15} Hz$
[2012]
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Answer:
Correct Answer: 33. (c)
Solution:
- (c) $n \to 2-1$
$E=10.2 eV$
$k E=E-\phi$
$Q=10.20-3.57$
$h v_0=6.63 eV$
$v_0=\frac{6.63 \times 1.6 \times 10^{-19}}{6.67 \times 10^{-34}}=1.6 \times 10^{15} Hz$
