Question

The magnetic torque exerted on a flat current-carrying loop of wire by a uniform magnetic field B is:

A) maximum when the plane of the loop is perpendicular to B
B) maximum when the plane of the loop is parallel to B
C) dependent on the shape of the loop for a fixed loop area
D) independent of the orientation of the loop
E) such as to rotate the loop around the magnetic field lines

Answer 1

The maximum magnetic torque on a current-carrying loop occurs when the plane of the loop is perpendicular to the magnetic field B, as torque is proportional to the sine of angle between the loop's normal and B.

Step-by-step explanation:

The magnetic torque exerted on a flat current-carrying loop of wire by a uniform magnetic field B is maximum when the plane of the loop is perpendicular to B. This is because the torque (τ) on a current-carrying loop in a magnetic field is given by τ = NIAB sin θ, where N is the number of turns in the loop, I is the current, A is the area of the loop, and θ is the angle between the normal to the plane of the loop and the magnetic field B.

At θ = 90 degrees, sin θ = 1, which results in the maximum torque. Conversely, when the plane of the loop is parallel to the field (θ = 0), sin θ = 0, resulting in zero torque. Therefore, the correct answer is: A) maximum when the plane of the loop is perpendicular to B.