Observing that the bulb does not glow in the circuit shown in Fig. (A) Boojho changed the circuit as shown in Fig. (B). He observed deflection in the magnetic compass.

$(a)$. What does the deflection in magnetic compass indicate?
$(b)$. Why did the bulb not glow in Fig. $(A)$?
$(c)$. What would be the effect of increase in the number of turns in the coil wound around the magnetic compass in Fig. $(B)$?
$(d)$. What will be observed if the number of cells are increased in the circuit shown in Fig. $(B)$?"

AcademicPhysicsNCERTClass 8

$(a)$. The deflection in the magnetic compass indicates that an electric current is passing through through the circuit.

$(b)$. The bulb did not glow in Fig. $(A)$ due to a weak current or the bulb being fused.

$(c)$. If the number of turns is increased in the coil, then the magnetic field will increase around the coil. This will increase deflection in the compass needle in $(B)$.

$(d)$. If the number of cells increases, then deflection will also increase in $(B)$.

Updated on 10-Oct-2022 13:29:30