Match List-I with List-II.
| List-I (Detector) | List-II (Radiation detected) |
|---|---|
| (A) Snakes | (I) Microwaves |
| (B) Many insects | (II) Infrared waves |
| (C) Speed gun used to time a fast ball | (III) Ultraviolet rays |
| (D) FM radio receiver | (IV) Radio waves |
Choose the correct answer from the options given below:
Answer & explanation
Correct answer: option 4
The correct answer is Option (4) → (A)-(II), (B)-(III), (C)-(I), (D)-(IV)
Different detectors respond to different parts of the electromagnetic spectrum. Even animals differ in the range of wavelengths they can sense.
(A) Snakes — This matches (II) Infrared waves. Snakes can detect infrared waves. This band lies just beyond the red, long-wavelength end of the visible spectrum.
(B) Many insects — This matches (III) Ultraviolet rays. For many insects, the ‘visible’ range goes well past violet into the ultraviolet.
(C) Speed gun used to time a fast ball — This matches (I) Microwaves. A speed gun works on the radar principle. Radar systems use microwaves because of their short wavelengths.
(D) FM radio receiver — This matches (IV) Radio waves. The FM band, \( 88\ \mathrm{MHz} \) to \( 108\ \mathrm{MHz} \), is part of the radio-wave region used for radio communication. Microwaves have much higher frequencies, in the \( \mathrm{GHz} \) range.
NCERT (2026-27):
8.4.4 Visible rays – “Different animals are sensitive to different range of wavelengths. For example, snakes can detect infrared waves, and the ‘visible’ range of many insects extends well into the utraviolet.”
8.4.2 Microwaves – “Due to their short wavelengths, they are suitable for the radar systems used in aircraft navigation. Radar also provides the basis for the speed guns used to time fast balls, tennis-serves, and automobiles.”
8.4.1 Radio waves – “… The FM (frequency modulated) radio band extends from 88 MHz to 108 MHz.”