CBSE 2022 · Region 2 · Set 1 · Q4 · 3 marks
(a)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.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.
(a)
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.
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
(a)
$\displaystyle E_y = E_0 \sin(kx - \omega t)$
$\displaystyle B_z = B_0 \sin(kx - \omega t)$
(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
Electromagnetic WavesApplyshort_answermedium
More from Electromagnetic Waves
- The ratio of amplitude of electric field to the amplitude of the magnetic field associated with an…2026 · asked 3×
- The magnetic field in a plane electromagnetic wave travelling in glass (n=1 · 5) is given by B y=(2 × 10^-7…2026 · asked 3×
- A plane electromagnetic wave travels through a medium and the magnetic field associated with it is given by…2026 · asked 3×
- How are infrared waves produced? Why are these waves referred to as heat waves? Give any two uses of infrared…2023 · asked 3×
- What is meant by the term 'displacement current'? Briefly explain how this current is different from a…2023 · asked 3×
- Identify electromagnetic waves which: (i) are used in radar system. (ii) affect a photographic plate. (iii)…2022 · asked 3×
- Which of the following electromagnetic waves has photons of largest momentum?2025 · asked 3×
- Depict the variation of electric field ( E) and magnetic field ( B) with respect to the direction of…2026 · asked 3×
CBSE Class 12 Physics past-paper question from the 2022board exam, with the answer as CBSE’s own marking scheme gives it. Where our answers come from.