CBSE Class 10 Science 2019 · Paper 31/4/2 · Question 4

Draw the solenoid (a long coil of many turns) connected to a cell, with the direction of the current marked in its turns, and draw its field lines as follows: (i) Inside the solenoid, the field lines are parallel, straight and equally spaced along its axis: the field inside is uniform. (ii) Outside, the lines come out of one end, spread out, curve round and enter the other end, like the field lines of a bar magnet; each line is a closed curve and no two lines cross. (iii) Polarity: the end at which the current, seen from outside, flows anticlockwise is the north pole (N); the end at which it flows clockwise is the south pole (S). (iv) Direction: outside the solenoid the lines point from N to S; inside, from S to N.