Problem

The magnetic field due to a current carrying circular loop of radius 3 m at a point on the axis at a distance of 4 m from the centre is

54 \mu\text{T}

. What will be its value at the centre of the loop? (a)

250 \mu\text{T}

(b)

150 \mu\text{T}

(c)

125 \mu\text{T}

(d)

75 \mu\text{T}