Electromagnetic Induction and Alternating Current 7 Question 13
####13. Two identical circular loops of metal wire are lying on a table without touching each other. Loop $A$ carries a current which increases with time. In response, the loop $B$
$(1999,2 \mathrm{M})$
(a) remains stationary
(b) is attracted by the loop $A$
(c) is repelled by the loop $A$
(d) rotates about its $\mathrm{CM}$, with $\mathrm{CM}$ fixed
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Answer:
Correct Answer: 13. (c)
Solution:
- For understanding, let us assume that the two loops are lying in the plane of paper as shown. The current in loop 1 will produce $\mathrm{U}$ magnetic field in loop 2 . Therefore, increase in current in loop 1 will produce an induced current in loop 2 which produces $\otimes$ magnetic field passing through it i.e. induced current in loop 2 will also be clockwise as shown in the figure.
The loops will now repel each other as the currents at the nearest and farthest points of the two loops flow in opposite directions.
