Question

9. A constant current flows in a horizontal wire in the plane of the

paper from east to west . The direction

of magnetic field at a point will be North to South

(a) directly above the wire

(b) directly below the wire

(c) at a point located in the plane of the paper, on the north side

of the wire

(d) at a point located in the plane of the paper, on the south

side of the wire

10. The strength of magnetic field inside a long current carrying

straight solenoid is

(a) more at the ends than at the centre

(b) minimum in the middle

(c) same at all points

(d) found to increase from one end to the other

Answer 1

9. The magnetic field lines will move from north to south directly below the paper.

10. The field lines are parallel inside (indicating that the magnetic field is uniform inside the solenoid) and curved outside the solenoid. This is similar to the magnetic field lines produced by a bar magnet.