Magnetic Field Due to a Current-Carrying Conductor

Magnetic field at the centre of a circular coil of radius $r$, through which a current $I$ flows is:

An electric current passes through a straight wire. Magnetic compasses are placed at the points $\mathrm{A}$ and $\mathrm{B}$

How is electromagnet made?

How will you use a solenoid to magnetise a steel bar?

What happens to the deflection of the compass needle placed at a point near current-carrying straight conductor
(a) If the current is increased,
(b) If the direction of current in the conductor is changed,
(c) If compass is moved away from the conductor?

State the factors on which the strength of magnetic field at a point due to a current-carrying conductor depends. State the rule which gives the direction of magnetic field.

A magnetic compass shows a deflection when placed near a current-carrying wire. How will the deflection of the compass needle get affected if the current in the wire is increased? Support your answer with a reason.

In what situation do we use right hand thumb rule?

When a compass needle is brought near a current-carrying conductor, the needle gets deflected. Why?

How is the strength of magnetic field around a current-carrying straight wire related to the magnitude of electric current flowing in the wire?

What does the direction of thumb indicates in the right hand thumb rule?