A rectangular loop rotates with a constant angular velocity about an axis as sho
ID: 2137971 • Letter: A
Question
A rectangular loop rotates with a constant angular velocity about an axis as shown. It makes one complete rotation in 0.04 s. The magnetic field lines are straight and parallel as shown. They are perpendicular to the axis of rotation. The lengths are c= 0.6 m and d= 4.3 m, the strength of the magnetic field is 0.07 T. The total resistance of the loop is 176 ?.
1)
A rectangular loop rotates with a constant angular velocity about an axis as shown. It makes one complete rotation in 0.04 s. The magnetic field lines are straight and parallel as shown. They are perpendicular to the axis of rotation. The lengths are c= 0.6 m and d= 4.3 m, the strength of the magnetic field is 0.07 T. The total resistance of the loop is 176 ?. What is the magnetic flux through the loop at the instant the normal to the loop makes an angle of 0 degree with the magnetic field? What is the magnetic flux through the loop at the instant the normal to the loop makes an angle of 30 degree with the magnetic field? What is the magnetic flux through the loop at the instant the normal to the loop makes an angle of 90 degree with the magnetic field? What is the angle between the normal to the loop and the B-field when the emf in the loop is at its maximum value? What is the maximum current I through the loop? At the instant when the current is a maximum, what torque (magnitude) must be applied by outside forces to keep the loop rotating at a constant angular velocity?Explanation / Answer
1) Flux = Fm = B A = 2 * .6 * 4.3 * .07 = .36 T
2) Flux = Fm cos 30 = .36 * cos 30 = .31 T
3) 0 cos 90 = 0
4) EMF = d flux/dt = Fm sin w t where w = 2 * pi * f (frequency)
When theta = 90 deg EMF is a max
5) EMF = .36 V (maximum) since sin w t = 1
6) Torque = 2 I c d B = 2 EMF * 4.3 * .07 * .6 / R = .00074 N-m
(Force on current carrying wire is I L B)
Related Questions
drjack9650@gmail.com
Navigate
Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.