Which of the following is an incorrect statement?

The correct answer is Option (2) → Iron loss cannot be minimised by taking laminated cores.

Each option is a statement about the energy losses in a transformer; the incorrect one is the answer.

(1) Copper loss can be minimised using thick wires. — Correct statement. The \( I^{2}R \) heating of the windings falls when thick wire of low resistance is used.

(2) Iron loss cannot be minimised by taking laminated cores. — Incorrect statement. The eddy currents in the iron core are reduced precisely by using a laminated core, thin insulated sheets that break up the current paths.

(3) Hysteresis loss can be minimised by using a magnetic material which has a low hysteresis loss. — Correct statement. The core is made of soft iron with a narrow hysteresis loop.

(4) Leakage of magnetic flux can be reduced by winding the primary over the secondary coil. — Correct statement. Winding one coil over the other makes nearly all the flux of one link the other.

NCERT (2026-27):
Transformers – “… (i) Flux Leakage: There is always some flux leakage; … It can be reduced by winding the primary and secondary coils one over the other. (ii) Resistance of the windings: … In high current, low voltage windings, these are minimised by using thick wire. (iii) Eddy currents: … The effect is reduced by using a laminated core. (iv) Hysteresis: … The resulting expenditure of energy in the core appears as heat and is kept to a minimum by using a magnetic material which has a low hysteresis loss.”