As shown in the figure, two solenoids are side by side. The switch S is initially open. When S is suddenly closed, the direction of the induced current through the resistor R is
A) from a to b.
B) from b to a.
C) No current is induced.

Question

As shown in the figure, two solenoids are side by side. The switch S is initially open. When S is suddenly closed, the direction of the induced current through the resistor R is 
A) from a to b. 
B) from b to a. 
C) No current is induced.

Quizplus · Accepted Answer

When the switch S is closed, the magnetic flux through the left solenoid changes, inducing an emf in the right solenoid in the opposite direction to its current. This results in a current flowing from b to a through resistor R, as shown by the right-hand rule for induced current.

As Shown in the Figure, Two Solenoids Are Side by Side