Match the LIST-I with LIST-II
| LIST-I | LIST-II | ||
| (Electromagnetic wave) | (Production method/device) | ||
| A. | Radio waves | I. | Magnetron valve |
| B. | Infrared | II. | Vibration of atoms/molecules |
| C. | Microwaves | III. | LC oscillator |
| D. | X-rays | IV. | Bombarding large atomic number metal target with fast moving electrons |
Choose the correct answer from the options given below:
Answer & explanation
Correct answer: option 4
The correct answer is Option (4) → A-III, B-II, C-I, D-IV
Each band of the spectrum is produced by a different source mechanism, set by its frequency.
(A) Radio waves — this matches (III) LC oscillator. Radio waves are produced by the accelerated motion of charges in oscillating circuits and antennas.
(B) Infrared — this matches (II) Vibration of atoms/molecules. Hot bodies emit infrared (heat waves) through the thermal vibration of their atoms and molecules.
(C) Microwaves — this matches (I) Magnetron valve. Microwaves are produced by special vacuum tubes such as the klystron, the magnetron and the Gunn diode.
(D) X-rays — this matches (IV) Bombarding large atomic number metal target with fast moving electrons. The electrons are decelerated in the target and knock out inner-shell electrons, which gives X-rays.
NCERT (2026-27):
Radio Waves – “Radio waves are produced by the accelerated motion of charges in conducting wires.”
Microwaves – “Microwaves (short-wavelength radio waves), with frequencies in the gigahertz (GHz) range, are produced by special vacuum tubes (called klystrons, magnetrons and Gunn diodes).”
Infrared Waves – “Infrared waves are produced by hot bodies and molecules.”
X-Rays – “… One common way to generate X-rays is to bombard a metal target by high energy electrons.”