The property which is not of an electromagnetic wave travelling in free space is that:
 1 the energy density in electric field is equal to energy density in magnetic field. 2 they travel with a speed equal to $$\dfrac{1}{\sqrt{\mu_0~ \varepsilon_0}} .$$ 3 they originate from charges moving with uniform speed. 4 they are transverse in nature.
Subtopic:  Properties of EM Waves |
62%
From NCERT
NEET - 2024
Hints

If $$\vec{E}$$ and $$\vec{B}$$ represent the electric field vector and magnetic field vector, respectively, in an electromagnetic wave then the direction of EM wave is along:
1. $$\vec{E}$$
2. $$\vec{B}$$
3. $$\vec{E}\times\vec{B}$$
4. $$\vec{B}\times\vec{E}$$
Subtopic:  Properties of EM Waves |
84%
From NCERT
NEET - 2024
Hints

If the ratio of relative permeability and relative permittivity of a uniform medium is $$1 : 4.$$ The ratio of the magnitudes of electric field intensity $$(E)$$ to the magnetic field intensity $$(H)$$ of an EM wave propagating in that medium is:
$$\left(\text{Given that}\sqrt{\frac{\mu_0}{\varepsilon_0}}=120\pi\right)$$
1. $$30\pi:1$$
2. $$1:120\pi$$
3. $$60\pi:1$$
4. $$120\pi:1$$
Subtopic:  Properties of EM Waves |
From NCERT
NEET - 2024
Hints

In a plane electromagnetic wave travelling in free space, the electric field component oscillates sinusoidally at a frequency of $$2.0\times 10^{10}~ \text{Hz}$$ and amplitude $$48~\text{Vm}^{-1}$$. Then the amplitude of the oscillating magnetic field is: (Speed of light in free space $$3\times 10^{8}~ \text{ms}^{-1}$$)
1. $$1.6 \times 10^{-6} ~\text{T}$$
2. $$1.6 \times 10^{-9} ~\text{T}$$
3. $$1.6 \times 10^{-8} ~\text{T}$$
4. $$1.6 \times 10^{-7} ~\text{T}$$
Subtopic:  Properties of EM Waves |
58%
From NCERT
NEET - 2023
Hints

$$\varepsilon_0$$ and $$\mu_0$$ are the electric permittivity and magnetic permeability of free space respectively. If the corresponding quantities of a medium are $$2\varepsilon_0$$ and $$1.5\mu_0$$ respectively, the refractive index of the medium will nearly be:
1. $$\sqrt2$$
2. $$\sqrt3$$
3. $$3$$
4. $$2$$
Subtopic:  Properties of EM Waves |
78%
From NCERT
NEET - 2023
Hints

When light propagates through a material medium of relative permittivity, $$\varepsilon_{r}$$ and relative permeability, $$\mu_{r}$$ the velocity of light, $$v$$ is given by:
($$c$$ = velocity of light in vacuum)
1. $$v=\dfrac{{c}}{\sqrt{\varepsilon_{r} \mu_{{r}}}}$$
2. $$v={c}$$
3. $$v=\sqrt{\dfrac{\mu_{{r}}}{\varepsilon_{{r}}}}$$
4. $$v=\sqrt{\dfrac{\varepsilon_{{r}}}{\mu_{{r}}}}$$
Subtopic:  Properties of EM Waves |
85%
From NCERT
NEET - 2022
To view explanation, please take trial in the course.
NEET 2025 - Target Batch
Hints
To view explanation, please take trial in the course.
NEET 2025 - Target Batch

An electromagnetic wave is moving along negative $$z (-z)$$ direction and at any instant of time, at a point, its electric field vector is $$3\hat j~\text{V/m}$$. The corresponding magnetic field at that point and instant will be: (Take $$c=3\times10^{8}~\text{ms}^{-1}$$)
 1 $$10\hat i~\text{nT}$$ 2 $$-10\hat i~\text{nT}$$ 3 $$\hat i~\text{nT}$$ 4 $$-\hat i~\text{nT}$$
Subtopic:  Properties of EM Waves |
53%
From NCERT
NEET - 2022
To view explanation, please take trial in the course.
NEET 2025 - Target Batch
Hints
To view explanation, please take trial in the course.
NEET 2025 - Target Batch

The magnetic field of a plane electromagnetic wave
is given by,
$$\vec B=3\times10^{-8}\text{cos}(1.6\times10^3x+48\times10^{10}t)\hat j~\text{T}.$$
The associated electric field will be:
 1 $$3 \times 10^{-8} \text{cos}\left(1.6 \times 10^3 x+48 \times 10^{10} t\right) \hat{i}~\text{ V/m}$$ 2 $$3 \times 10^{-8} \text{sin} \left(1.6 \times 10^3 {x}+48 \times 10^{10} {t}\right) \hat{{i}}~ \text{V} / \text{m}$$ 3 $$9 \text{sin} \left(1.6 \times 10^3 {x}-48 \times 10^{10} {t}\right) \hat{{k}} ~~\text{V} / \text{m}$$ 4 $$9 \text{cos} \left(1.6 \times 10^3 {x}+48 \times 10^{10} {t}\right) \hat{{k}}~~\text{V} / \text{m}$$
Subtopic:  Properties of EM Waves |
56%
From NCERT
NEET - 2022
To view explanation, please take trial in the course.
NEET 2025 - Target Batch
Hints
To view explanation, please take trial in the course.
NEET 2025 - Target Batch

The ratio of the magnitude of the magnetic field and electric field intensity of a plane electromagnetic wave in free space of permeability $$\mu_0$$ and permittivity $$\varepsilon_0$$ is:
(Given that $$c=$$ velocity of light in free space)
1.  $$c$$
2.  $$\dfrac1c$$
3.  $$\dfrac{c}{\sqrt{\mu_0\varepsilon_0}}$$
4.  $$\dfrac{\sqrt{\mu_0\varepsilon_0}}{c}$$
Subtopic:  Properties of EM Waves |
58%
From NCERT
NEET - 2022
To view explanation, please take trial in the course.
NEET 2025 - Target Batch
Hints
To view explanation, please take trial in the course.
NEET 2025 - Target Batch

For a plane electromagnetic wave propagating in the $$x$$-direction, which one of the following combinations gives the correct possible directions for the electric field $$(E)$$ and magnetic field $$(B)$$ respectively?
1. $$\hat{j}+\hat{k},~-\hat{j}-\hat{k}$$
2. $$-\hat{j}+\hat{k},~-\hat{j}+\hat{k}$$
3. $$\hat{j}+\hat{k},~\hat{j}+\hat{k}$$
4. $$-\hat{j}+\hat{k},~-\hat{j}-\hat{k}$$
Subtopic:  Properties of EM Waves |
From NCERT
NEET - 2021
To view explanation, please take trial in the course.
NEET 2025 - Target Batch
Hints