Question

What are magnetic field lines? How is the direction of the 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 magnetic field around a current-carrying wire can be visualized using the right-hand rule, where your thumb points in the direction of the current and the curl of your fingers shows the magnetic field direction.

Answer 1

F₂Magnetic Field Lines: Magnetic field lines indicate the direction and intensity of a magnetic field. These lines originate from the north pole and terminate at the south pole. The closer the field lines are, the stronger the magnetic field at that location.

F₂Direction of Magnetic Field: The direction of the magnetic field at any point is found using the F₂right-hand rule. If you curl the fingers of your right hand in the direction of the current in a wire, your thumb points in the direction of the magnetic field lines.

F₂Magnetic Field Due to a Current-Carrying Circular Loop:
For a circular loop carrying current, the magnetic field lines create concentric circles around the wire and pass through the center of the loop. The magnetic field is strongest at the center of the loop and weakens with distance from the center.

\[\text{Current:} \quad \rightarrow \quad \text{Clockwise or Counter-clockwise depending on the view.}\] \[\text{Magnetic Field Lines:} \quad \rightarrow \quad \text{Form circular loops around the current.}\]
F₂Factors Affecting the Magnitude of the Magnetic Field:
The magnitude of the magnetic field produced by a current-carrying coil is affected by:
1. F₂Current (I): A larger current produces a stronger magnetic field.
2. F₂Number of turns (N): More turns in the coil result in a stronger magnetic field.