1
JEE Main 2021 (Online) 27th July Morning Shift
+4
-1
The relative permittivity of distilled water is 81. The velocity of light in it will be :

(Given $$\mu$$r = 1)
A
4.33 $$\times$$ 107 m/s
B
2.33 $$\times$$ 107 m/s
C
3.33 $$\times$$ 107 m/s
D
5.33 $$\times$$ 107 m/s
2
JEE Main 2021 (Online) 25th July Morning Shift
+4
-1
A linearly polarized electromagnetic wave in vacuum is

$$E = 3.1\cos \left[ {(1.8)z - (5.4 \times {{10}^6})t} \right]\widehat iN/C$$

is incident normally on a perfectly reflecting wall at z = a. Choose the correct option
A
The wavelength is 5.4 m
B
The frequency of electromagnetic wave is 54 $$\times$$ 104 Hz.
C
The transmitted wave will be $$3.1\cos \left[ {(1.8)z - (5.4 \times {{10}^6})t} \right]\widehat iN/C$$
D
The reflected wave will be $$3.1\cos \left[ {(1.8)z + (5.4 \times {{10}^6})t} \right]\widehat iN/C$$
3
JEE Main 2021 (Online) 22th July Evening Shift
+4
-1
Intensity of sunlight is observed as 0.092 Wm$$-$$2 at a point in free space. What will be the peak value of magnetic field at the point?

($${\varepsilon _0} = 8.85 \times {10^{ - 12}}{C^2}{N^{ - 1}}{m^{ - 2}}$$)
A
2.77 $$\times$$ 10$$-$$8 T
B
1.96 $$\times$$ 10$$-$$8 T
C
8.31 T
D
5.88 T
4
JEE Main 2021 (Online) 20th July Evening Shift
+4
-1
In an electromagnetic wave the electric field vector and magnetic field vector are given as $$\overrightarrow E = {E_0}\widehat i$$ and $$\overrightarrow B = {B_0}\widehat k$$ respectively. The direction of propagation of electromagnetic wave is along :
A
$$\left( {\widehat k} \right)$$
B
$$\widehat j$$
C
$$\left( { - \widehat k} \right)$$
D
$$\left( { - \widehat j} \right)$$
EXAM MAP
Medical
NEET