MATHEMATICS · Subjective · ISC · Physics · Magnetic Effects of Current and Magnetism · Ampere's circuital law
Problem
In a laboratory, a straight vertical wire carries a current of 4.0 A. The magnetic field strength measured at a point 5 cm from the wire is found to be 8 µT.
(i) Keeping the current unchanged, calculate the magnetic field strength at a point 10 cm from the wire.
(ii) Keeping the current unchanged, calculate the magnetic field strength at a point 2.5 cm from the wire.
(iii) Comment on the pattern you observe from your answers in parts (i) and (ii).