MATHEMATICS · Single correct · ISC · Physics · Magnetic Effects of Current and Magnetism · Ampere's circuital law
Problem
A straight wire carries a steady current. Points P, Q and R are situated at distances 2 cm, 4 cm and 8 cm from the wire respectively. Which one of the following correctly ranks the magnetic field strength at these points, from strongest to weakest?
(a) R > Q > P
(b) P = Q = R
(c) P > Q > R
(d) Q > P > R