Q. No.For a certain metal, when monochromatic light of wavelength \(\lambda\)
1. \(1\)
2. \(4\)
3. \(2\)
4. \(3\)
1. \(1\)
2. \(4\)
3. \(2\)
4. \(3\)
Subtopic: Einstein's Photoelectric Equation |
89%
Level 1: 80%+
Please attempt this question first.
Hints
Please attempt this question first.
Light source having wavelength \(331 ~\text {nm}\) to generate photo-electrons whose stopping potential is \(0.2~\text{V}\). The work function of the used metal in the experiment is \(\alpha \times 10^{-19} ~\text{J} .\) The value of \(\alpha\) is:
\(\left({h}=6.62 \times 10^{-34} \text{J s}, {e}=1.6 \times 10^{-19}~\text{C} \text { and } {c}=3 \times 10^8~ \text{m/s}\right)\)
1. \(3.68\)
2. \(4.68\)
3. \(5.68\)
4. \(2.68\)
\(\left({h}=6.62 \times 10^{-34} \text{J s}, {e}=1.6 \times 10^{-19}~\text{C} \text { and } {c}=3 \times 10^8~ \text{m/s}\right)\)
1. \(3.68\)
2. \(4.68\)
3. \(5.68\)
4. \(2.68\)
Subtopic: Einstein's Photoelectric Equation |
65%
Level 2: 60%+
Please attempt this question first.
Hints
Please attempt this question first.
\(K_1\) and \(K_2\) be the maximum kinetic energies of photoelectrons emitted from a surface of a given material for the light of wavelength \(\lambda_1\) \(\lambda_2\) \(\lambda_1=2\lambda_2\)
1. \(K_2+2K_1\)
2. \(2K_2-K_1\)
3. \(K_1-2K_2\)
4. \(K_2-2K_1\)
1. \(K_2+2K_1\)
2. \(2K_2-K_1\)
3. \(K_1-2K_2\)
4. \(K_2-2K_1\)
Subtopic: Einstein's Photoelectric Equation |
63%
Level 2: 60%+
Please attempt this question first.
Hints
Please attempt this question first.
The graph shows variations of stopping potential \(V_0\) with the frequency \(\nu\) of the incident radiation for three photosensitive metals \(X_1,X_2~ \text{and} ~X_3.\) Which metal will give out electrons with greater kinetic energy, for the same wavelength of incident radiation?
1. \(X_1\)
2. \(X_2\)
3. \(X_3\)
4. All the metals will give out photo electrons with same kinetic energies.
1. \(X_1\)
2. \(X_2\)
3. \(X_3\)
4. All the metals will give out photo electrons with same kinetic energies.
Subtopic: Einstein's Photoelectric Equation |
73%
Level 2: 60%+
Please attempt this question first.
Hints
Please attempt this question first.
A light wave described by \(E = 60[\sin(3\times 10^{15})t+\sin(12\times 10^{15})t]\) (in SI units) falls on a metal surface of work function \(2.8~\text{eV}\). The maximum kinetic energy of ejected photoelectron is (approximately): (in eV)
(\(h = 6.6\times 10^{-34}~\text{J.s}~\text{and}~e = 1.6\times 10^{-19}~\text{C}\).)
1. \(5.1\)
2. \(3.8\)
3. \(6.0\)
4. \(7.8\)
(\(h = 6.6\times 10^{-34}~\text{J.s}~\text{and}~e = 1.6\times 10^{-19}~\text{C}\).)
1. \(5.1\)
2. \(3.8\)
3. \(6.0\)
4. \(7.8\)
Subtopic: Einstein's Photoelectric Equation |
83%
Level 1: 80%+
Please attempt this question first.
Hints
Please attempt this question first.
Light is incident on a metallic plate having work function \(110\times 10^{20} ~\text {J}.\) If the produced photoelectrons have zero kinetic energy then the angular frequency of the incident light is: (in rad/s)
\((h=6.63\times 10^{-34} ~\text{J.s})\)
1. \(1.04\times 10^{16}\)
2. \(1.04\times 10^{13}\)
3. \(1.66\times 10^{16}\)
4. \(1.66\times 10^{15}\)
\((h=6.63\times 10^{-34} ~\text{J.s})\)
1. \(1.04\times 10^{16}\)
2. \(1.04\times 10^{13}\)
3. \(1.66\times 10^{16}\)
4. \(1.66\times 10^{15}\)
Subtopic: Einstein's Photoelectric Equation |
73%
Level 2: 60%+
Please attempt this question first.
Hints
Please attempt this question first.
When a light of a given wavelength falls on a metallic surface the stopping potential for photoelectrons is \(\text 3.2~\text{V}.\) If a second light having wavelength twice of first light is used, the stopping potential drops to \(\text 0.7~\text{V}.\) The wavelength of first light is: (in m)
\(\left(h=6.63 \times 10^{-34} ~\text{J.s}, ~{e}=1.6 \times 10^{-19} ~\text{C}, {c}=3 \times 10^8 ~\text{m/s}\right)\)
1. \(\text 2.9 \times 10^{-8}\)
2. \(\text 2.2 \times 10^{-8}\)
3. \(\text 3.1 \times 10^{-7}\)
4. \(\text 2.5 \times 10^{-7}\)
\(\left(h=6.63 \times 10^{-34} ~\text{J.s}, ~{e}=1.6 \times 10^{-19} ~\text{C}, {c}=3 \times 10^8 ~\text{m/s}\right)\)
1. \(\text 2.9 \times 10^{-8}\)
2. \(\text 2.2 \times 10^{-8}\)
3. \(\text 3.1 \times 10^{-7}\)
4. \(\text 2.5 \times 10^{-7}\)
Subtopic: Einstein's Photoelectric Equation |
69%
Level 2: 60%+
Please attempt this question first.
Hints
Please attempt this question first.
Given below are two statements:
In the light of the above statements, choose the correct answer from the options given below:
| Assertion (A): | In photoelectric effect, on increasing the intensity of incident light the stopping potential increases. |
| Reason (R): | Increase in intensity of light increases the rate of photoelectrons emitted, provided the frequency of incident light is greater than threshold frequency. |
| 1. | Both (A) and (R) are True and (R) is the correct explanation of (A). |
| 2. | Both (A) and (R) are True but (R) is not the correct explanation of (A). |
| 3. | (A) is True but (R) is False. |
| 4. | (A) is False but (R) is True. |
Subtopic: Einstein's Photoelectric Equation |
69%
Level 2: 60%+
Please attempt this question first.
Hints
Please attempt this question first.
A monochromatic light is incident on a metallic plate having work function \(\phi\). An electron, emitted normally to the plate from a point \(A\) with maximum kinetic energy, enters a constant magnetic field, perpendicular to the initial velocity of electron. The electron passes through a curve and hits back the plate at a point \(B.\) The distance between \(A\) and \(B\) is: (Given: The magnitude of charge of an electron is \(e \) and mass is \(m, h \) is Planck's constant and \(c\) is velocity of light. Take the magnetic field exists throughout the path of electron)
1. \(\dfrac{\sqrt{2 {~m}({hc} / \lambda-\phi)}} { {eB} }\)
2. \(\dfrac{\sqrt{8 {~m}({hc} / \lambda-\phi)}} { {eB} }\)
3. \(\dfrac{\sqrt{{~m}({hc} / \lambda-\phi)}} { {eB} }\)
4. \(\dfrac{2\sqrt{{~m}({hc} / \lambda-\phi)}} { {eB} }\)
1. \(\dfrac{\sqrt{2 {~m}({hc} / \lambda-\phi)}} { {eB} }\)
2. \(\dfrac{\sqrt{8 {~m}({hc} / \lambda-\phi)}} { {eB} }\)
3. \(\dfrac{\sqrt{{~m}({hc} / \lambda-\phi)}} { {eB} }\)
4. \(\dfrac{2\sqrt{{~m}({hc} / \lambda-\phi)}} { {eB} }\)
Subtopic: Einstein's Photoelectric Equation |
Level 4: Below 35%
Please attempt this question first.
Hints
Please attempt this question first.
In the photoelectric effect, the stopping potential \(V_0\) v/s frequency \(v\) curve is plotted.
(\(h\) is Planck's constant and \(\phi_0\) is the work function of metal)
Choose the correct answer from the options given below -
1. (A), (C) and (E) only
2. (C) and (D) only
3. (A), (B) and (C) only
4. (D) and (E) only
(\(h\) is Planck's constant and \(\phi_0\) is the work function of metal)
| (A) | \(V_0\) v/s \(v\) is linear |
| (B) | The slope of \(V_0\) v/s \(v\) curve =\(\dfrac{\phi_0}{h}\) |
| (C) | \(h\) constant is related to the slope of \(V_0\) v/s \(v\) line. |
| (D) | The value of the electric charge of an electron is not required to determine h using the \(V_0\) v/s \(v\) curve. |
| (E) | The work function can be estimated without knowing the value of \(h.\) |
1. (A), (C) and (E) only
2. (C) and (D) only
3. (A), (B) and (C) only
4. (D) and (E) only
Subtopic: Einstein's Photoelectric Equation |
90%
Level 1: 80%+
Please attempt this question first.
Hints
Please attempt this question first.
© 2026 GoodEd Technologies Pvt. Ltd.