In a transformer, the energy loss due to flux leakage can be reduced by
Answer & explanation
Correct answer: option 1
The correct answer is Option (1) → winding the primary and secondary coils one over the other
Flux leakage means that part of the flux produced by the primary does not pass through the secondary. To reduce it, the two coils are kept as close together as possible.
Option (1) winding the primary and secondary coils one over the other — Correct. With one coil wound over the other, nearly all the flux of the primary also passes through the secondary.
Option (2) using thick wire for the windings — Incorrect. Thick wire lowers the resistance of the windings. It reduces the heat lost in the wire (\( I^{2}R \)), which is a different loss.
Option (3) placing the primary and secondary coils on separate limbs of the core — Incorrect. This is the other way of winding a transformer. With the coils apart, more of the flux can escape before it reaches the secondary.
Option (4) increasing the number of turns in the primary coil — Incorrect. The number of turns sets the ratio of the secondary and primary voltages. It does not make more of the flux pass through the secondary.
NCERT (2026-27):
Transformers – “(i) Flux Leakage: There is always some flux leakage; that is, not all of the flux due to primary passes through the secondary due to poor design of the core or the air gaps in the core. It can be reduced by winding the primary and secondary coils one over the other.”