Question

What are magnetic field lines? How is the direction of magnetic field at a point determined? Draw the pattern of magnetic field lines of the magnetic field produced by a current-carrying circular loop. Mark on it the direction of (i) current and (ii) magnetic field lines. Name the two factors on which the magnitude of the magnetic field due to a current-carrying coil depends.

Hint:

The right-hand thumb rule helps determine the direction of magnetic field lines around a current-carrying wire. The magnetic field lines form concentric circles around the wire, with the field direction determined by the right hand rule.

Answer 1

Magnetic field lines are the imaginary lines used to represent the magnetic field in space. The field lines show the direction and the strength of the magnetic field. The direction of the magnetic field at any point is defined as the direction of the force that would act on a positive magnetic pole placed at that point. Direction of Magnetic Field at a Point:
The direction of the magnetic field at a point is determined by the right-hand thumb rule. According to this rule:
- If you hold the current-carrying wire with your right hand such that your thumb points in the direction of the current, your fingers will curl around the wire in the direction of the magnetic field lines.
Magnetic Field due to a Current-Carrying Circular Loop: When a current flows through a circular loop, it produces a magnetic field in the form of concentric circles around the wire. The magnetic field at the center of the loop is along the axis of the loop. To draw the pattern of magnetic field lines:
- The magnetic field lines form concentric circles around the wire.
- The direction of the field lines is determined using the right-hand thumb rule.
In the center of the loop, the field lines are nearly straight and parallel to the axis of the loop.