A long cylindrical solenoid of length has closely wound turns and carries a current of
PHYSICS · Subjective · CBSE · Physics · Magnetic Effects of Electric Current · Magnetic Effects of Electric Current
Problem
A long cylindrical solenoid of length 50cm has 800 closely wound turns and carries a current of 2A. Let the end marked X be the one at which the current enters the upper surface of the winding.
(i) Identify which end of the solenoid (X or the opposite end) behaves as its north pole. Give proper reasoning.
(ii) A magnetic needle is placed just outside the midpoint of the solenoid on its side surface. Predict and explain the orientation that the needle will take.
(iii) The current in the solenoid is now reversed in direction. State the change, if any, in each of the following, giving reasons:
(a) direction of magnetic field inside the solenoid,
(b) polarity of the two ends,
(c) orientation of the magnetic needle placed as in part (ii).