A battery is connected between two points A and B on the circumference of a uniform conducting ring of radius r and resistance R. One of the arcs AB of the ring subtends an angle θ at the centre. The value of the magnetic induction at the centre due to the current in the ring is
1
proportional to 2(180° – θ)
2
inversely proportional to r
3
zero, only if θ = 180°
4
zero for all values of θ