Electromagnetic Induction and Alternating Current 7 Question 11
11. As shown in the figure, $P$ and $Q$ are two coaxil conducting loops separated by some distance. When the switch $S$ is closed, a clockwise current $I _p$ flows in $P$ (as seen by $E$ ) and an induced current $I _{Q _1}$ flows in $Q$. The switch remains closed for a long time. When $S$ is opened, a current $I _{Q _2}$ flows in $Q$.
Then the direction $I _{Q _1}$ and $I _{Q _2}$ (as seen by $E$ ) are $(2002,2 M)$
(a) respectively clockwise and anti-clockwise
(b) both clockwise
(c) both anti-clockwise
(d) respectively anti-clockwise and clockwise
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Answer:
Correct Answer: 11. (d)
Solution:
- When switch $S$ is closed magnetic field lines passing through $Q$ increases in the direction from right to left. So, according to Lenz’s law, induced current in $Q$ i.e. $I _{Q _1}$ will flow in such a direction, so that the magnetic field lines due to $I _{Q _1}$ passes from left to right through $Q$.
This is possible when $I _{O _1}$ flows in anti-clockwise direction as seen by $E$. Opposite is the case when switch $S$ is opened i.e. $I _{Q _2}$ will be clockwise as seen by $E$.
