✓ Board-verified
Physics · 2022 · 3 marks
CBSE 2022 · Region 2 · Set 1 · Q4
(a) (i) Depict a plane electromagnetic wave propagating along the x-axis. Write the expressions for its oscillating electric and magnetic fields.…
(a)(i)
Depict a plane electromagnetic wave propagating along the x-axis. Write the expressions for its oscillating electric and magnetic fields.
(ii)
Write three characteristics of electromagnetic waves.
OR
(b)
Name the electromagnetic waves which are produced by the following :
(i)
Radioactive decays of nucleus
(ii)
Welding arcs
(iii)
Hot bodies Write one use each of these waves.
Marking-scheme solution
(i)
$\displaystyle E_y = E_0 \sin(kx - \omega t)$
$\displaystyle B_z = B_0 \sin(kx - \omega t)$
(ii)
The three characteristics are:
(a)
They travel with velocity of light.
(b)
They carry energy and momentum.
(c)
They are transverse in nature.
(a)
Gamma Rays - Used for cancer treatment
(b)
Ultraviolet/Visible/Infrared (either) – Use of anyone of these three.
(c)
Infrared Rays – Used in night vision camera, bolometer & thermopiles
All Electromagnetic Waves questions2022 question paperNCERT solutions: Electromagnetic WavesPractice Electromagnetic Waves →
More from Electromagnetic Waves
- The ratio of amplitude of electric field to the amplitude of the magnetic field associated with an electromagnetic wave propagating in glass (n=1 ·…2026
- The magnetic field in a plane electromagnetic wave travelling in glass (n=1 · 5) is given by B_y=(2 × 10^-7 T) sin (α x+1 · 5 × 10^11 t) where x is…2026
- What are infrared waves? Why are these waves referred to as 'heat waves'? Give any two uses of these waves.2026
- Differentiate between conduction current and displacement current. A capacitor is connected across a source providing time-dependent current. Explain…2026
- Which one of the following has the highest frequency?2024
- The electromagnetic waves used in radar systems are:2023
- What are microwaves? How are they produced? Give any two uses of microwaves.2026
- Which one of the following electromagnetic radiation has the least wavelength?2023
CBSE Class 12 Physics past-paper question from the 2022 board exam, with the answer as CBSE’s own marking scheme gives it. Where our answers come from.