JEE Main 2023 (Online) 24th January Morning Shift | Electromagnetic Waves Question 44 | Physics

1

JEE Main 2023 (Online) 24th January Morning Shift

MCQ (Single Correct Answer)

+4

-1

In $$\overrightarrow E $$ and $$\overrightarrow K $$ represent electric field and propagation vectors of the EM waves in vacuum, then magnetic field vector is given by :

($$\omega$$ - angular frequency) :

A

$${1 \over \omega }\left( {\overline K \times \overline E } \right)$$

B

$$\overline K \times \overline E $$

C

$$\omega \left( {\overline K \times \overline E } \right)$$

D

$$\omega \left( {\overline E \times \overline K } \right)$$

2

JEE Main 2022 (Online) 29th July Morning Shift

MCQ (Single Correct Answer)

+4

-1

Match List - I with List - II :

	List - I		List - II
(a)	UV rays	(i)	Diagnostic tool in medicine
(b)	X-rays	(ii)	Water purification
(c)	Microwave	(iii)	Communication, Radar
(d)	Infrared wave	(iv)	Improving visibility in foggy days

Choose the correct answer from the options given below :

A

(a)-(iii), (b)-(ii), (c)-(i), (d)-(iv)

B

(a)-(ii), (b)-(i), (c)-(iii), (d)-(iv)

C

(a)-(ii), (b)-(iv), (c)-(iii), (d)-(i)

D

(a)-(iii), (b)-(i), (c)-(ii), (d)-(iv)

3

JEE Main 2022 (Online) 28th July Evening Shift

MCQ (Single Correct Answer)

+4

-1

Sun light falls normally on a surface of area $$36 \mathrm{~cm}^{2}$$ and exerts an average force of $$7.2 \times 10^{-9} \mathrm{~N}$$ within a time period of 20 minutes. Considering a case of complete absorption, the energy flux of incident light is

A

$$25.92 \times 10^{2} \mathrm{~W} / \mathrm{cm}^{2}$$

B

$$8.64 \times 10^{-6} \mathrm{~W} / \mathrm{cm}^{2}$$

C

$$6.0 \mathrm{~W} / \mathrm{cm}^{2}$$

D

$$0.06\mathrm{~W} / \mathrm{cm}^{2}$$

4

JEE Main 2022 (Online) 27th July Evening Shift

MCQ (Single Correct Answer)

+4

-1

Identify the correct statements from the following descriptions of various properties of electromagnetic waves.

(A) In a plane electromagnetic wave electric field and magnetic field must be perpendicular to each other and direction of propagation of wave should be along electric field or magnetic field.

(B) The energy in electromagnetic wave is divided equally between electric and magnetic fields.

(C) Both electric field and magnetic field are parallel to each other and perpendicular to the direction of propagation of wave.

(D) The electric field, magnetic field and direction of propagation of wave must be perpendicular to each other.

(E) The ratio of amplitude of magnetic field to the amplitude of electric field is equal to speed of light.

Choose the most appropriate answer from the options given below :

A

(D) only

B

(B) and (D) only

C

(B), (C) and (E) only

D

(A), (B) and (E) only