explain through an activity current carrying circular coil
Answers
Apparatus Required :
Rectangular cardboard having two holes, Thick copper circular coils of different radii having known number of turns, key, battery, rheostat, stand, iron filings.
Procedure :
(i) Pass the coil through the two holes of cardboard in such a way that half of the loop is above the cardboard and remaining part should be below it and normal to the plane of cardboard. (ii) Connect the circuit as shown in fig.1
(iii) Sprinkle iron filings uniformly on the cardboard.
(iv) Allow the current to pass though the coil by inserting plug in the key.
(v) Note the pattern of iron filings that emerges on the cardboard after tapping gently a few times. (Observation).
(vi) Place the compass at any point over the pattern of field. Observe the direction of needle.
2). Observations :
(a) Iron filings are arranged in the form of concentric circles.
(b) The concentric circles become larger and larger as we move away from the wire.
(c) At the centre of loop, lines are almost straight and perpendicular to the plane of the loop.
Conclusion :
(i) The concentric circles at every point of a current carrying circular loop represent the magnetic field around it.
(ii) Magnetic field line close to the axis of loop is straight and is perpendicular to the plane of the coil.
(iii) Field lines keep on diverging as we move away from the centre of loop.