MULTIPLE CHOICE 789 ULTIPLE CHOICE 341 Faradays Experiments

MULTIPLE CHOICE 789 ULTIPLE CHOICE 34-1 Faraday\'s Experiments 2 Faraday\'s Law of Induction A uniform magnetic B perpendicular to a wire loop varies with time as shown in Fig. 34-20a. Which of the plots in Fig. 34-20b best represents the induced current in the loop a function of time? as 6. The current through the coil on the right in Fig. 3-2 varies as shown in Fig. 34-22a. Which graph in Fig. 34-22b best shows the ammeter reading as a function of time? A flexible conducting loop is in the shape of a circle with a variable radius. The loop is in a uniform magnetic field per pendicular to the plane of the loop To sustain a constant emf in the loop, the radius r must vary with time according (C) (B) (D) should be constant. 3 A flexible wire loop in the shape of a circle has a radius that grows linearly with time. There is a magnetic field perpendic- ular to the plane of the loop that has a magnitude inversely proportional to the distance from the center of loop. Bu) How does the emf E vary with time? 7. The long, straight wire in Fig. 34-23 camies a constant cument i to the right. What is the direction of the induced current in (B) the wise loop? DO is The magnetic flux through a wire loop changes by 44 in a time Ar The change in flux 44, is proportional to (C) There is no induced cument. (A) the current in the wire. the resistance of the wire in the (C) the net charge that flows across any cross section (D) the potential difference between any two fixed points 34-3 Lenz Law A bar magnet drops through a wire loop, which graph in Fig. 24-21 best shows how the current through the loop varies time? Assume that a negative current refers to a current FIGURE 34-23. Multiple choice questions 7, 5.9 and 11. flowing in the reverse direction.

Solution

1) A

2) B

3) B

4) D

5) D

6) C

7) B

8) B

9) C

10) C

11)

a) A

b) B

C) B

12) E

13) C

14) A

15) A

16) D

17)

a) A

b) B

18) B