Question

An electric current I flows through a circular loop as shown in Figure 2(b) below. Write an expression and direction for the magnetic field at the centre of the loop at point P.

Answer 1

`because` The current is in anticlockwise direction, therefore magnetic field created is given by right hand thumb rule.

Here, the magnetic field created ic out of the plane of paper

`B = (mu_0I)/(2a)`  

where  a = radius of the coil.