We have four coils, of similar shape and size, made up from iron, copper, aluminium, and nichrome Class 8

We have four coils, of similar shape and size, made up from iron, copper, aluminium, and nichrome as shown in Fig. 4.12. Class 8

We have four coils, of similar shape and size, made up from iron, copper, aluminium, and nichrome as shown in Fig. 4.12.

When current is passed through the coils, compass needles placed near the coils will show deflection. Class 8

(i) Only in circuit (a)

(ii) Only in circuits (a) and (b)

(iii) Only in circuits (a), (b), and (c)

(iv) In all four circuits

Answer:

(iv) In all four circuits

(The compass needles placed near the coils will show deflection in all the four cases. The deflection however will not be equal in all the four cases. The magnetic strength of the electromagnet depends on the nature of the material used)