The earth’s magnetic field at a given point is 0.5 x 10–5 Wb m–2. This field is to be annulled by magnetic induction at the centre of a circular conducting loop of radius 5.0 cm. The current reqired to be flown in the loop is nearly
Answer & explanation
Correct answer: option 2
The magnetic field due to a circular loop at the centre is given by $B = \frac{\mu_0 I}{2r} \Rightarrow I = \frac{2Br}{\mu_0}$
B = 0.5 x 10–5 Wb m–2
r = 5cm
$\Rightarrow I = 0.4A$