A current carrying wire is in the shape of an equilateral triangle of edge lengt
ID: 1583048 • Letter: A
Question
A current carrying wire is in the shape of an equilateral triangle of edge length 4.0 cm. The triangle lies in the z = 0 plane. The wire carries a current of 1.6 A.
(a) What is the magnitude of the torque on the wire if it is in a region with a uniform magnetic field of magnitude 0.34 T that points in the +z direction?
...................N·m
(b) What is the magnitude of the torque on the wire if it is in a region with a uniform magnetic field of magnitude 0.34 T that points in the +x direction?
..................................N·m
Explanation / Answer
Given length a = 4 cm = 0.04 m
Area of an equilateral triangle is
A = (3/4)*a^2
A = (3/4) * (0.04)^2
A = 6.93 * 10^-4 m^2
current I = 1.6 A
The torque on a loop in a magnetic field is given by
T = I * A * B * sin(theta)
theta is the angle between Area vector and the magnetic field
a)
Here magnetic field and area vector are in +z direction so sin(theta) = 0 hence
torque T = 0
b)
Here theta = 90 so sin(theta) = 1
therefore T = I * A * B
T = 1.6 * 6.93 * 10^-4 * 0.34
T = 3.77 * 10^-4 N-m