CBSE Class 10 Science 2020 · Paper 31/3/1 · Question 23

(i) A current-carrying solenoid behaves like a bar magnet, its two ends acting as the north and south poles. The magnetic field is strong near these poles (ends), where the field lines are crowded: the lines, parallel inside the solenoid, spread out (diverge) as they come out of the north-pole end and come together (converge) as they go into the south-pole end, each forming a closed loop. (ii) A current-carrying solenoid behaves like a bar magnet, so when it is suspended freely the Earth's magnetic field turns it, like a compass needle, until it rests along the north-south direction. (iii) A fuse of higher rating would not melt even when a current greater than the safe limit flows, so the wiring and appliances would be damaged; a fuse of lower rating would melt even with the normal current. A fuse of identical rating melts just when the current exceeds the safe limit, so it protects the circuit.