The diagram shows an inductor that is part of a circuit. The direction of the emf induced in the inductor is indicated. Which of the following is possible?
A) The current is constant and rightward
B) The current is constant and leftward
C) The current is increasing and rightward
D) The current is increasing and leftward
E) None of the above

Question

The diagram shows an inductor that is part of a circuit. The direction of the emf induced in the inductor is indicated. Which of the following is possible? 
A) The current is constant and rightward 
B) The current is constant and leftward 
C) The current is increasing and rightward 
D) The current is increasing and leftward 
E) None of the above

Quizplus · Accepted Answer

According to Lenz's law, the induced emf in an inductor always opposes the change in current that produced it. Therefore, since the direction of the induced emf is leftward, the current in the circuit must be increasing and moving in the opposite direction (rightward) in order to produce this opposing emf. Therefore, the best choice is D, where the current is increasing and leftward.

The Diagram Shows an Inductor That Is Part of a Circuit