A long straight copper wire is stretched tightly in the north–south direction 1 cm…
PHYSICS · Multi-part · CBSE · Physics · Magnetic Effects of Electric Current · Magnetic Effects of Electric Current
Problem
A long straight copper wire is stretched tightly in the north–south direction 1 cm above the pivot of a freely suspended magnetic compass kept in a classroom laboratory.
(i) A steady current of 3 A is passed from south to north through the wire. State clearly whether the north pole of the compass needle will deflect towards the east or towards the west. Give a reason for your answer.
(ii) The same wire is now shifted so that it lies 1 cm due east of the compass in its original north–south orientation, and the current is kept flowing from south to north. In which direction will the north pole of the needle now move? Explain your reasoning.
(iii) State any two changes that can be made in the experimental set-up to increase the magnitude of the needle’s deflection without altering the direction obtained in part (i). Justify your suggestions.