| 1 | IR-Rays | A | Photocells |
| 2 | X-Rays | B | The eyes |
| 3 | UV-Rays | C | Thermopiles Bolometer |
| 4 | Visible light | D | Ionization Chamber |
Answer & explanation
Correct answer: option 4
The LHS gives the part of the electromagnetic spectrum and RHS gives its detection methods.