A regular polygon of n sides is formed by bending a wire of total length `2 pi r` which carries a current i. (a) Find the magnetic field B at the centre of the polygon. (b) By letting `n rarr oo` , deduce the expression for the magnetic field at the centre of a circular current.

A square loop of wire of side a carries a current i . Calculate the magnetic field at the centre of the loop

Find the magnetic field B at the centre of a rectangular loop of length l and width b, carrying a current i.

A cirular coil of wire cansiting of 100 turns ,each of readius 8.0 cm carries a current of 0.40 A. What is the magnitude of the magnetic field barB at the centre of the coil ?

A wire of length 2m carries a current of 1A is bend to form a circle. The magnetic moment of the coil is:

A current of 2*00 A exists in a square loop of edge 10*0 cm . Find the magnetic field B at the centre of the square loop.

A long wire carrying a steady current is bent into a circular loop of one turn. The magnetic field at the centre of the loop is B. It is then bent into a circular coil of n turns. The magnetic field at the centre of this coil of n turns will be

A wire of length l is bent in the form of an equilateral triangle and carries an electric current i. (a) Find the magnetic field B at the centre. (b) If the wire is bent in the form of a square, what would be the value of B at the centre?

A circular loop of one turn carries a current of 5.00 A. If the magnetic field B at the centre is 0.200 mT, find the radius of the loop.

A conducting circular loop of radius a is connected to two long, straight wires . The straight wires carry a current I as shown in figure . Find the magnetic field B at the centre of the loop.

A tightly- wound solenoid of radius a and length l has n turns per unit length. It carries an electric current i. Consider a length dx of the solenoid at a distance x from one end. This contains n dx turns and may be approximated as a circular current I n dx. (a) Write the magnetic field at the center of the solenoid due to this circular current. Integrate this expression under proper limits to find the magnetic field at the center of the solenoid. (b) Verify that if lgtgta , the field tends to (B=(mu_0ni) and if agtgt1 , the field tends to B= ((mu_0)nil/2a) . Interpret these results.