JEE Main 2021 (Online) 25th July Morning Shift | Magnetics Question 96 | Physics

JEE Main 2021 (Online) 25th July Morning Shift

MCQ (Single Correct Answer)

-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

The wavelength is 5.4 m

The frequency of electromagnetic wave is 54 $$\times$$ 10⁴ Hz.

The transmitted wave will be $$3.1\cos \left[ {(1.8)z - (5.4 \times {{10}^6})t} \right]\widehat iN/C$$

The reflected wave will be $$3.1\cos \left[ {(1.8)z + (5.4 \times {{10}^6})t} \right]\widehat iN/C$$

JEE Main 2021 (Online) 22th July Evening Shift

MCQ (Single Correct Answer)

-1

Choose the correct option

True dip is always equal to apparent dip.

True dip is not mathematically related to apparent dip.

True dip is less than the apparent dip.

True dip is always greater than the apparent dip.

JEE Main 2021 (Online) 22th July Evening Shift

MCQ (Single Correct Answer)

-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?

($${\varepsilon _0} = 8.85 \times {10^{ - 12}}{C^2}{N^{ - 1}}{m^{ - 2}}$$)

2.77 $$\times$$ 10^$$-$$8 T

1.96 $$\times$$ 10^$$-$$8 T

8.31 T

5.88 T

JEE Main 2021 (Online) 22th July Evening Shift

MCQ (Single Correct Answer)

-1

Statement I : The ferromagnetic property depends on temperature. At high temperature, ferromagnet becomes paramagnet.

Statement II : At high temperature, the domain wall area of a ferromagnetic substance increases.

In the light of the above statements, choose the most appropriate answer from the options given below :

Statement I is false but Statement II is true

Statement I is true but Statement II is false

Both Statement I and Statement II are false

Both Statement I and Statement II are true

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