Question

 Part A

 A conducting rod is being dragged along conducting rails, as shown in (Figure 1). The magnetic field is directed out of the screen. In what direction does the

 induced current flow through the light bulb?

  There is no induced current.

  The induced current flows through the bulb from the left to the right.

  The induced current flows through the bulb from the right to the left.

 Part B

 A circular loop of conducting wire is moving through a uniform magnetic field, as shown in (Figure 2). Is a non-zero emf induced in the loop?

  Yes

  No

 Part C

 A wire loop is rotating at a constant angular frequency within a uniform magnetic field B. The orientation of the magnetic field is shown at three moments in

 time below. [Hint. you may want to watch the video again starting at 05:55

 Rank the orientations from lowest to highest magnitude of the instantaneous induced emf.

 Part D

 Two loops of wire, each having a different radius, encircle an infinitely long solenoid, as shown in (Figure 3). The magnetic field B is zero outside the solenoid The current through the solenoid is increasing with time, causing the magnetic field inside the solenoid to increase with time. Which statements?

  The emf around wire loops 1 and 2 is zero since there is no magnetic field outside the solenoid.

  The emf around the two-wire loops is the same and is non-zero.

  The emf around wire loop 2 is greater than that of loop 1.

Answer 1

Part A )

as the conducting rod is dragged, the area enclosed decreases which in turn decreases the magnetic flux in outward direction. hence the current is induced in the loop so as to increase the magnetic flux in outward direction. hence the induced magnetic field by the induced current in the loop must be outward. For producing induced magnetic field in outward direction, using the right hand rule, the induced current must be in counter-clockwise direction.

The induced current flows through the bulb from the right to the left.

Part B)

No

Since the magnetic flux linked with the circular coil is not changing, no current is induced.

Part C)

EX PL IN WA .. Lowest

D)

The Rate of change of magnetic flux is same for both the loops, hence same emf is induced in each loop

The emf around the two wire loops is the same and is non-zero.