A rectangular loop consists of 112 closely wrapped turns and has dimensions 0.40
ID: 1790843 • Letter: A
Question
A rectangular loop consists of 112 closely wrapped turns and has dimensions 0.400 m by 0.300 m. The loop is hinged along the y axis, and the plane of the coil makes an angle of 30.00 with the x-axis (see figure below). 0.40 m 30.0° 0.30 m What is the magnitude of the torque exerted on the loop by a uniform magnetic field of 0.744 T directed along the x-axis when the current in the windings has a value of 1.20 A in the direction shown? N·m What is the expected direction of rotation of the loop? O clockwise as viewed from above O counterclockwise as viewed from the above O The magnitude is zero.Explanation / Answer
We know that the formula for Torque is
= NBIAsin
is defined as an angle perpendicular to the plane of the loop, so it is 60o
A = (.4)(.3) = .12 m2
= (112)(.744)(1.2)(.12)(sin60)
T = 10.39Nm
The direction of the the rotation will be determined by the right hand rule. The current on the nonhinged side is moving in the negative y direction, the magnetic field is given to be in the positive x direction. Therefore the force will rotate the loop clockwise as viewed from above.