Question

Draw a labeled diagram showing the magnetic field lines of a loop carrying current. Mark the direction of current and the direction of magnetic field by arrows in your diagram.

Answer 1

Hint: As a first step, you could draw a current loop connected to a cell and a key. Then you could mark the direction of the current in the loop, which is very important because it is this direction that determines direction of field lines. The magnetic field lines for a circular current carrying loop, if you may recall, are concentric circles around the loop that decrease in concentration as you move away from the coil. You could draw these concentric circles around the loop and then mark its direction using the right hand thumb rule.

Complete step-by-step answer:
We know that, when electric current flows through a circular coil, it produces magnetic field lines. If you consider any point in the current carrying loop, the magnetic field lines formed are in the form of concentric circles around that coil at the point under consideration. However, as the distance from the circular loop increases, the concentration of field lines decreases. Also, concentration of field lines on the inside is more when compared to that of outside. And you could see that the magnetic field line at the centre is a straight line.

We could find the direction of the field lines using the right hand thumb rule. In order to use the thumb rule, all you have to do is to curl your right hand palm around the circular wire with your fingers pointing at the direction of current, and then your thumb gives you the direction of the magnetic field.
From the figure, you could see that, at the left hand side where current flow is in upward direction, has magnetic field lines in the anticlockwise direction and at the right hand side where the current flow is in the downward direction has the field lines in clockwise direction. As mentioned above, you could see that at the centre the magnetic field line is a straight line.
The side of the loop in which the magnetic field lines appear to arise from can be considered as a north pole and the side in which these field lines appear to end could be considered a south pole. In other words, a circular loop carrying current acts as a magnetic dipole.

Note: While drawing the diagram, make sure that you draw the field lines more concentrated on the inside than the outside. Also remember that the magnetic field line at the centre is straight. Direction is a very important part of the diagram, so, use the right hand thumb rule and carefully determine the direction of the field line from the direction current.