Match List-I with List-II
| List-I | List-II | ||
|---|---|---|---|
| (EM Waves) | (Detectors) | ||
| (A) | Radio waves | (I) | Geiger Tubes |
| (B) | Microwaves | (II) | Photocells |
| (C) | X-rays | (III) | Receiver’s aerials |
| (D) | Ultraviolet rays | (IV) | Point Contact Diodes |
Choose the correct answer from the options given below:
Answer & explanation
Correct answer: option 4
The correct answer is Option (4) → (A) - (III), (B) - (IV), (C) - (I), (D) - (II)
Each part of the spectrum is detected by a device that responds to its wavelength and energy.
(A) Radio waves — this matches (III) Receiver’s aerials. The long waves induce currents in the aerial (antenna) of the receiver.
(B) Microwaves — this matches (IV) Point Contact Diodes. Microwave signals are detected by point contact crystal diodes.
(C) X-rays — this matches (I) Geiger Tubes. X-rays ionise the gas in a Geiger tube (photographic film and ionisation chambers are also used).
(D) Ultraviolet rays — this matches (II) Photocells. UV photons are energetic enough to eject electrons from the cathode of a photocell.
NCERT (2026-27):
Gamma Rays – …
