Dual Nature of Radiation and Matter - Result Question 31

«««< HEAD:content/english/neet-pyq-chapterwise/physics/dual-nature-of-radiation-and-matter/dual-nature-of-radiation-and-matter-result-question-31.md

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 :

======= ####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 :

3e0f7ab6f6a50373c3f2dbda6ca2533482a77bed:content/english/neet-pyq-chapterwise/physics/dual-nature-of-radiation-and-matter/dual-nature-of-radiation-and-matter—result-question-31.md (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]

Show Answer

Answer:

Correct Answer: 33. (c)

Solution:

  1. (c) $n \to 2-1$

$E=10.2 eV$

$k E=E-\phi$

$Q=10.20-3.57$

$h v_0=6.63 eV$

$v_0=\frac{6.63 \times 1.6 \times 10^{-19}}{6.67 \times 10^{-34}}=1.6 \times 10^{15} Hz$