PHYS 102 – Chapter 31 – Review Problems

1. A single-turn plane loop of wire of cross sectional area 40 cm2 is perpendicular to a magnetic field that increases uniformly in magnitude from 0.5 T to 5.5 T in 2.0 seconds. What is the resistance of the wire if the induced current is 1.0 mA?

1. A rectangular loop of wire is placed midway between two long straight parallel conductors as shown in figure 1. The conductors carry currents I1 and I2 as indicated. If I1 is increasing and I2 is constant, what is the direction of the induced current in the loop?

1. A magnet is taken towards a metallic ring in such a way that a constant current of 0.01 A is induced in it. The total resistance of the ring is 0.25 W. In 10 seconds, by how much does the flux of the magnetic field through the ring change?

1. Consider a circular loop of wire within which, the magnetic flux, FB, is given as a function of time as: FB = a t2 + b , where a and b are constants. If the induced emf is 48 V at t = 3 s, what is the value of a?

1. A 2.0-T uniform magnetic field makes an angle of 60o with the xy plane. What is the magnetic flux through an area of 3-m2 portion of the xy plane?

1. Figure 2 shows a conducting bar moving with a constant speed of 5.0 m/s to the right. Assume that R = 5.0 W, L = 0.20 m, and that a uniform magnetic field of 3.5 T is directed into the page. Calculate the magnitude of the applied force pulling the bar.

M.F. Al-Kuhaili