1
JEE Main 2024 (Online) 31st January Morning Shift
MCQ (Single Correct Answer)
+4
-1

When a metal surface is illuminated by light of wavelength $$\lambda$$, the stopping potential is $$8 \mathrm{~V}$$. When the same surface is illuminated by light of wavelength $$3 \lambda$$, stopping potential is $$2 \mathrm{~V}$$. The threshold wavelength for this surface is:

A
3$$\lambda$$
B
9$$\lambda$$
C
5$$\lambda$$
D
4.5$$\lambda$$
2
JEE Main 2024 (Online) 30th January Evening Shift
MCQ (Single Correct Answer)
+4
-1

For the photoelectric effect, the maximum kinetic energy $$\left(E_k\right)$$ of the photoelectrons is plotted against the frequency $$(v)$$ of the incident photons as shown in figure. The slope of the graph gives

A
Planck's constant
B
Work function of the metal
C
Charge of electron
D
Ratio of Planck's constant to electric charge
3
JEE Main 2024 (Online) 30th January Evening Shift
MCQ (Single Correct Answer)
+4
-1

If the total energy transferred to a surface in time $$\mathrm{t}$$ is $$6.48 \times 10^5 \mathrm{~J}$$, then the magnitude of the total momentum delivered to this surface for complete absorption will be:

A
$$2.16 \times 10^{-3} \mathrm{~kg} \mathrm{~m} / \mathrm{s}$$
B
$$2.46 \times 10^{-3} \mathrm{~kg} \mathrm{~m} / \mathrm{s}$$
C
$$1.58 \times 10^{-3} \mathrm{~kg} \mathrm{~m} / \mathrm{s}$$
D
$$4.32 \times 10^{-3} \mathrm{~kg} \mathrm{~m} / \mathrm{s}$$
4
JEE Main 2024 (Online) 30th January Morning Shift
MCQ (Single Correct Answer)
+4
-1

The work function of a substance is $$3.0 \mathrm{~eV}$$. The longest wavelength of light that can cause the emission of photoelectrons from this substance is approximately;

A
215 nm
B
400 nm
C
414 nm
D
200 nm
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