A long straight wire has a constant current flowing to the right. A rectangular metal loop is situated above the wire, and also has a constant current flowing through it, as shown in the figure. Which one of the following statements is true?
A) The net magnetic force on the rectangle is upward, and there is also a nonzero torque on the rectangle.
B) The net magnetic force on the rectangle is zero, and the net torque on it is zero.
C) The net magnetic force on the rectangle is downward, and there is also a nonzero torque on the rectangle.
D) The net magnetic force on the rectangle is zero, but there is a nonzero torque on the rectangle.
E) The net magnetic force on the rectangle is downward, and the net torque on it is zero.

Question

A long straight wire has a constant current flowing to the right. A rectangular metal loop is situated above the wire, and also has a constant current flowing through it, as shown in the figure. Which one of the following statements is true? 
A) The net magnetic force on the rectangle is upward, and there is also a nonzero torque on the rectangle. 
B) The net magnetic force on the rectangle is zero, and the net torque on it is zero. 
C) The net magnetic force on the rectangle is downward, and there is also a nonzero torque on the rectangle. 
D) The net magnetic force on the rectangle is zero, but there is a nonzero torque on the rectangle. 
E) The net magnetic force on the rectangle is downward, and the net torque on it is zero.

Quizplus · Accepted Answer

The Answer of A long straight wire has a constant current flowing to the right. A rectangular metal loop is situated above the wire, and also has a constant current flowing through it, as shown in the figure. Which one of the following statements is true? 
A) The net magnetic force on the rectangle is upward, and there is also a nonzero torque on the rectangle. 
B) The net magnetic force on the rectangle is zero, and the net torque on it is zero. 
C) The net magnetic force on the rectangle is downward, and there is also a nonzero torque on the rectangle. 
D) The net magnetic force on the rectangle is zero, but there is a nonzero torque on the rectangle. 
E) The net magnetic force on the rectangle is downward, and the net torque on it is zero.

A Long Straight Wire Has a Constant Current Flowing to the Right