How will the magnetic field at the centre of a circular coil carrying current change, if the diameter as well as number of turns in the coil is tripled?

How will the magnetic field intensity at the centre of a circular coil carrying current change, if the current through the coil is doubled and the radius of the coil is halved?

Derive an expression for magnetic field at the centre of circular current carrying coil.

How does the strength of the magnetic field at the centre of a circular coil of a wire depend on:(a)radius of the coil(b) number of turns of coil.

Derive an expression for the magnetic field.at the centre of a current carrying coil.

State whether the following statements are true or false: The field at the centre of a long circular coil carrying current will be parallel straight lines.