Question

Draw a diagram to represent the magnetic field lines along the axis of a current carrying solenoid. Mark arrows to show the direction of current in the solenoid and the direction of magnetic field lines.

Answer 1

Hint: As we know that, in a solenoid whenever current flows through the wire a strong magnetic field arises in the coil. The direction of the magnetic field depends on the direction of current. Discuss how it works and how the magnitude of the magnetic field is calculated from the formula.

Complete step by step answer:

FIG: Diagram to represent the magnetic field lines along the axis of a current carrying solenoid.

In this diagram magnetic field lines are shown along the axis of a current carrying solenoid.
In a solenoid whenever current flows through the wire a strong magnetic field arises in the coil. The direction of the magnetic field depends on the direction of current.

The work of a solenoid is to generate a magnetic field which converts the electrical current into mechanical motion and force (example- electrical switch).
By using Ampere’s circuital law to the loop, we can calculate the magnitude of the magnetic field.
First, we have to take a rectangular path and then apply the Ampere’s law,
$BL = \mu NI$
$B = \mu \left( {\dfrac{N}{L}} \right)I = \mu nI$
Where $B$ is the magnetic field of the solenoid, $N$ is the number of turns in the solenoid, $I$ is current in the coil, $L$ is length of the coil.

By using this equation, we can calculate the magnitude of the magnetic field.

Note: The magnetic field inside the coil is constant while the strength of magnetic field is lower in the outer side. The strength of the magnetic field does not depend on the diameter of the solenoid and the position inside the solenoid.