JEE Main 2022 · 25 June · morning · Single correct · +4 / −1
Match List-I with List-II.
Choose the correct answer from the options given below :
| List - I | List -II | ||
|---|---|---|---|
| (A) | AC generator | (I) | Detects the presence of current in the circuit |
| (B) | Galvanometer | (II) | Converts mechanical energy into electrical energy |
| (C) | Transformer | (III) | Works on the principle of resonance in AC circuit |
| (D) | Metal detector | (IV) | Changes an alternating voltage for smaller or greater value |
- (a) (A) - (II), (B) - (I), (C) - (IV), (D) - (III)
- (b) (A) - (II), (B) - (I), (C) - (III), (D) - (IV)
- (c) (A) - (III), (B) - (IV), (C) - (II), (D) - (I)
- (d) (A) - (III), (B) - (I), (C) - (II), (D) - (IV)
Answer and solution
Answer (a) (A) - (II), (B) - (I), (C) - (IV), (D) - (III)
Solution
Physics sir · 4 steps
Ask what each device actually does for you, and the matching falls into place one pair at a time.
- Pin the easy two. An AC generator spins a coil in a magnetic field, turning mechanical energy into electrical energy: (A)–(II). A galvanometer is the meter that shows whether a current is flowing: (B)–(I).
- Transformer. A transformer uses mutual induction between two coils to step an AC voltage up or down. The voltage ratio follows the turns ratio, so (C)–(IV).
Vₛ/Vₚ = Nₛ/Nₚ
- Metal detector. A metal detector has an LCR circuit tuned to resonance. A metal object nearby changes the inductance, the circuit goes off resonance, and the drop in current sets off the alarm. So (D)–(III).
- So. The matching is (A)–(II), (B)–(I), (C)–(IV), (D)–(III), which is option (a).
The idea to keep. In match-the-column questions, fix the pairs you are sure of first and strike out options. Remember: transformer means mutual induction and voltage change, metal detector means resonance in an LCR circuit.
Answer from the NTA final answer key. Solution by PrepWiser.