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

In a plane EM wave, the electric field oscillates sinusoidally at a frequency of $$5 \times 10^{10} \mathrm{~Hz}$$ and an amplitude of $$50 \mathrm{~Vm}^{-1}$$. The total average energy density of the electromagnetic field of the wave is : [Use $$\varepsilon_0=8.85 \times 10^{-12} \mathrm{C}^2 / \mathrm{Nm}^2$$ ]

A
$$4.425 \times 10^{-8} \mathrm{Jm}^{-3}$$
B
$$2.212 \times 10^{-10} \mathrm{Jm}^{-3}$$
C
$$2.212 \times 10^{-8} \mathrm{Jm}^{-3}$$
D
$$1.106 \times 10^{-8} \mathrm{Jm}^{-3}$$
2
JEE Main 2024 (Online) 30th January Morning Shift
MCQ (Single Correct Answer)
+4
-1
Change Language

The electric field of an electromagnetic wave in free space is represented as $$\overrightarrow{\mathrm{E}}=\mathrm{E}_0 \cos (\omega \mathrm{t}-\mathrm{kz}) \hat{i}$$. The corresponding magnetic induction vector will be :

A
$$\overrightarrow{\mathrm{B}}=\mathrm{E}_0 \mathrm{C} \cos (\omega \mathrm{t}+\mathrm{k} z) \hat{j}$$
B
$$\overrightarrow{\mathrm{B}}=\frac{\mathrm{E}_0}{\mathrm{C}} \cos (\omega \mathrm{t}-\mathrm{kz}) \hat{j}$$
C
$$\overrightarrow{\mathrm{B}}=\mathrm{E}_0 \mathrm{C} \cos (\omega \mathrm{t}-\mathrm{k} z) \hat{j}$$
D
$$\overrightarrow{\mathrm{B}}=\frac{\mathrm{E}_0}{\mathrm{C}} \cos (\omega \mathrm{t}+\mathrm{kz}) \hat{j}$$
3
JEE Main 2024 (Online) 29th January Evening Shift
MCQ (Single Correct Answer)
+4
-1
Change Language

A plane electromagnetic wave of frequency $$35 \mathrm{~MHz}$$ travels in free space along the $$X$$-direction. At a particular point (in space and time) $$\vec{E}=9.6 \hat{j} \mathrm{~V} / \mathrm{m}$$. The value of magnetic field at this point is :

A
$$9.6 \hat{j} T$$
B
$$3.2 \times 10^{-8} \hat{i} T$$
C
$$9.6 \times 10^{-8} \hat{k} T$$
D
$$3.2 \times 10^{-8} \hat{k} T$$
4
JEE Main 2024 (Online) 27th January Evening Shift
MCQ (Single Correct Answer)
+4
-1
Change Language

An object is placed in a medium of refractive index 3 . An electromagnetic wave of intensity $$6 \times 10^8 \mathrm{~W} / \mathrm{m}^2$$ falls normally on the object and it is absorbed completely. The radiation pressure on the object would be (speed of light in free space $$=3 \times 10^8 \mathrm{~m} / \mathrm{s}$$ ) :

A
$$6 \mathrm{~Nm}^{-2}$$
B
$$36 \mathrm{~Nm}^{-2}$$
C
$$18 \mathrm{~Nm}^{-2}$$
D
$$2 \mathrm{~Nm}^{-2}$$
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