When you close the switch S in the figure, the potential between A and B drops to zero. The current in the top loop does not immediately drop to zero because
A) the top loop has less resistance than the bottom loop.
B) an EMF is generated in the inductor L.
C) an EMF is generated in the resistor R.
D) the current depends only on the resistance in the circuit.
E) Kirchhoff's junction rule states that the current into a junction must equal the current out of the junction.

Question

When you close the switch S in the figure, the potential between A and B drops to zero. The current in the top loop does not immediately drop to zero because
A) the top loop has less resistance than the bottom loop. 
B) an EMF is generated in the inductor L. 
C) an EMF is generated in the resistor R. 
D) the current depends only on the resistance in the circuit. 
E) Kirchhoff's junction rule states that the current into a junction must equal the current out of the junction.

Quizplus · Accepted Answer

When the switch S is closed, the current in the top loop will start to decrease as the potential difference across the inductor begins to decrease. However, due to the self-inductance of the inductor, an electromotive force (EMF) is generated that opposes the decrease in current. This is described by Lenz's law, which states that the direction of the induced EMF is such that it opposes the change in current that causes it. Therefore, the current in the top loop does not immediately drop to zero, but rather continues to flow as the inductor opposes the change in current.

When You Close the Switch S in the Figure, the Potential