1
JEE Main 2024 (Online) 30th January Evening Shift
MCQ (Single Correct Answer)
+4
-1
Change Language

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
$$4.32 \times 10^{-3} \mathrm{~kg} \mathrm{~m} / \mathrm{s}$$
2
JEE Main 2024 (Online) 30th January Morning Shift
MCQ (Single Correct Answer)
+4
-1
Change Language

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
3
JEE Main 2024 (Online) 29th January Evening Shift
MCQ (Single Correct Answer)
+4
-1
Change Language

Two sources of light emit with a power of $$200 \mathrm{~W}$$. The ratio of number of photons of visible light emitted by each source having wavelengths $$300 \mathrm{~nm}$$ and $$500 \mathrm{~nm}$$ respectively, will be :

A
$$5: 3$$
B
$$3: 5$$
C
$$1: 5$$
D
$$1: 3$$
4
JEE Main 2024 (Online) 29th January Morning Shift
MCQ (Single Correct Answer)
+4
-1
Change Language

The de-Broglie wavelength of an electron is the same as that of a photon. If velocity of electron is $$25 \%$$ of the velocity of light, then the ratio of K.E. of electron and K.E. of photon will be:

A
$$\frac{1}{4}$$
B
$$\frac{8}{1}$$
C
$$\frac{1}{8}$$
D
$$\frac{1}{1}$$
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