A laboratory requires a magnetic field of at the centre of a circular coil of wire
PHYSICS · Subjective · CBSE · Physics · Moving Charges and Magnetism · Moving Charges and Magnetism
Problem
A laboratory requires a magnetic field of 1.0×10−3T at the centre of a circular coil of wire. The available power supply can provide a steady current of 4 A.
(i) For a coil of radius 15 cm, calculate the minimum number of turns needed to produce the required magnetic field.
(ii) If the same current is used but the coil radius is reduced to 10 cm, determine the new number of turns required to maintain the field at 1.0×10−3T.
(iii) Explain why reducing the radius changes the required number of turns in the manner found.