SATHEE: Modern Physics 2 Question 21

Modern Physics 2 Question 21

20. For photo-electric effect with incident photon wavelength $λ$ , the stopping potential is $V_{0}$ . Identify the correct variation(s) of $V_{0}$ with $λ$ and $\frac{1}{λ}$ .

(2015 Adv.) (a)

(c)

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Solution:

$\begin{aligned} e V_{0} & = \frac{h c}{λ} - W \\ V_{0} & = \frac{h c}{e} \frac{1}{λ} - \frac{W}{e} \end{aligned}$

$V_{0}$ versus $\frac{1}{λ}$ graph is in the form $y = m x - c$

Therefore option (c) is correct.

Clearly, $V_{0}$ versus $λ$ graph is not a straight line but $V_{0}$ decreases with increase in $λ$ and $V_{0}$ becomes zero when $\frac{h c}{λ} = W$ .

$i.e.$

$λ = λ_{0}$

(Threshold wavelength)

$∴$ Option (a) is also correct.

Modern Physics 2 Question 21

20. For photo-electric effect with incident photon wavelength $λ$ , the stopping potential is $V_{0}$ . Identify the correct variation(s) of $V_{0}$ with $λ$ and $\frac{1}{λ}$ .

Solution:

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Modern Physics 2 Question 21

20. For photo-electric effect with incident photon wavelength λ, the stopping potential is V0. Identify the correct variation(s) of V0 with λ and 1λ.

Solution:

Engineering Preparation

Medical Preparation

NCERT Books & Solutions

Important Resources

Other Resources

Syllabus

Test Platform

Sample Mock Test

Mentorship

NCERT Exercise Video Solution

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20. For photo-electric effect with incident photon wavelength $λ$ , the stopping potential is $V_{0}$ . Identify the correct variation(s) of $V_{0}$ with $λ$ and $\frac{1}{λ}$ .