Question

What are magnetic field lines ? list three characteristics of these lines. Describe in brief an activity to study the magnetic field lines due to a current flowing in a circular coil

CBSE Class X Science SA 2 (3 Marks)

Answer 1

Representation of the magnetic field path along which an imaginary free north pole would tend to move. The tangent at any point on the magnetic field line gives the direction of the magnetic field at that point. Characteristics of magnetic field lines : (a) Emerge at north pole and merge at south pole. Inside the magnet, the direction of field lines is from south pole of magnet to its north pole, are closed curves. (b) At the points where the magnetic field is stronger, field lines are crowded and vice-versa. (c) No two magnetic field lines can intersect each other. 3 Activity : Take a long wire and pass it through the cardboard such that half the wire is above it and remaining part is below the cardboard. Join the free ends of the wire to a battery through a plug key. Insert the key and pass the current. Sprinkle iron filings on the cardboard and tap gently. You will find concentric circles are formed which are centered at the point where the wire passes through the cardboard.

Answer 2

Answer:

Representation of the magnetic field path along which an imaginary free north pole would tend to move. The tangent at any point on the magnetic field line gives the direction of the magnetic field at that point. Characteristics of magnetic field lines : (a) Emerge at north pole and merge at south pole. Inside the magnet, the direction of field lines is from south pole of magnet to its north pole, are closed curves. (b) At the points where the magnetic field is stronger, field lines are crowded and vice-versa. (c) No two magnetic field lines can intersect each other. 3 Activity : Take a long wire and pass it through the cardboard such that half the wire is above it and remaining part is below the cardboard. Join the free ends of the wire to a battery through a plug key. Insert the key and pass the current. Sprinkle iron filings on the cardboard and tap gently. You will find concentric circles are formed which are centered at the point where the wire passes through the cardboard.