Question

Deflection in the galvanometer.

A) Towards right
B) Left
C) No deflection
D) None of these

Answer 1

Hint: In order to solve this question, knowledge of the principle of solenoid and galvanometer is important. The concept that when a magnet is brought near the solenoid connected in a closed circuit will induce current in the solenoid is necessary. The direction of the flow of current would depend on which pole of the magnet is brought close to the solenoid. The direction of flow of current will be different for the North Pole and different for the South Pole. The direction of deflection of the needle in the galvanometer would depend on the direction of flow of current.

Complete step by step answer:
Here in this question, initially the given magnet is stationary which means it is not moving and in this condition there will be no deflection in the needle of the galvanometer. Hence, the pointer in the galvanometer reads zero.

But as the given in this question, that the south pole of the magnet is brought near the solenoid, when the south pole of the magnet comes towards the solenoid, the current starts flowing through the solenoid and the galvanometer shows deflection.

As the south pole of the magnet is brought closer to the solenoid, hence the direction of the flow of current would be clockwise direction which will make the galvanometer to show deflection towards the left.

Hence, option B, Left is the correct answer.

Note: Solenoid can be defined as the long cylindrical coil of wire with a large number of turns in it. It is important in a solenoid that the length of the solenoid should be greater than its diameter. When a magnet is brought towards the solenoid connected in a closed circuit, it induces current in the solenoid. If the north is brought close then the direction of flow of current would be anti-clockwise, if the South Pole is brought near the solenoid then the direction of flow of current in the solenoid would be clockwise.