Question

L is a circular ring made of a uniform wire. Current enters and leaves the ring through straight conductors which, if produced, would have passed through the centre C of the ring. What is the magnetic field at C?

• A. Due to the straight conductors is zero
• B. Due to the loop is zero
• C. Due to the loop is proportional to $\theta$
• D. Due to the loop is proportional to $(\pi -\theta )$

Answer 1

Answer: (A), (B)

The correct options are
A Due to the straight conductors is zero
B Due to the loop is zero

Magnetic field due to the straight conductors is zero since the incoming and outgoing wires will produce equal and opposite magnetic field there.
Since there is no current in the loop so magnetic filed due to the loop is zero.