JEE Main 2023 · 15 April · morning · Single correct · +4 / −1
Match List I with List II of Electromagnetic waves with corresponding wavelength range :
Choose the correct answer from the options given below:
| List I | List II |
|---|---|
| (A) Microwave | (I) 400 nm to 1 nm |
| (B) Ultraviolet | (II) 1 nm to 10⁻³ nm |
| (C) X-Ray | (III) 1 mm to 700 nm |
| (D) Infra-red | (IV) 0.1 m to 1 mm |
- (a) (A)-(I), (B)-(IV), (C)-(II), (D)-(III)
- (b) (A)-(IV), (B)-(I), (C)-(II), (D)-(III)
- (c) (A)-(IV), (B)-(I), (C)-(III), (D) -(II)
- (d) (A)-(IV), (B)-(II), (C)-(I), (D)-(III)
Answer and solution
Answer (b) (A)-(IV), (B)-(I), (C)-(II), (D)-(III)
Solution
Physics sir · 3 steps
Line up the spectrum by wavelength, from microwave down to X-rays, and fix visible light in the middle.
- Order the waves. From longest to shortest wavelength the order is microwave, infrared, visible, ultraviolet, X-ray. The visible band, about 700 nm to 400 nm, splits the list into two halves.
- Use the visible edges. Infrared sits just beyond red, so it ends at 700 nm. Ultraviolet sits just beyond violet, so it starts at 400 nm.
Wave Position in spectrum Wavelength range Match (A) Microwave longest of the four 0.1 m to 1 mm (IV) (D) Infra-red just longer than red light 1 mm to 700 nm (III) (B) Ultraviolet just shorter than violet light 400 nm to 1 nm (I) (C) X-Ray shortest of the four 1 nm to 10⁻³ nm (II) - So. The matching is (A)-(IV), (B)-(I), (C)-(II), (D)-(III), which is option (b).
The idea to keep. Learn the EM spectrum as one ordered list and fix the visible band at 400 to 700 nm. Every neighbouring range then joins on at a shared edge.
Answer from the NTA final answer key. Solution by PrepWiser.