1. A rectangular loop is placed in a uniform
magnetic field with the plane of the loop
perpendicular to the direction of the field.
If a current is made to flow through the loop
in the sense shown by the arrows, the field
exerts on the loop:
1. a net force.
2. a net torque.
3. a net force and a net torque.
4. neither a net force nor a net torque. PI I

2. A rectangular loop is placed in a uniform
magnetic field with the plane of the loop
parallel to the direction of the field.
If a current is made to flow through the loop
in the sense shown by the arrows, the field
exerts on the loop:
1. a net force.
2. a net torque.
3. a net force and a net torque.
4. neither a net force nor a net torque. PI I

3. What is for this current loop?

4. A rectangular loop of wire carries a current I in a magnetic field
Which of the following gives the torque on the loop?

5. i o
Loop area = A θ
1. What is the magnetic flux through the wire loop of area A above?
(a) AB (b) AB cosθ (c) AB sinθ (d) zero
2. If θ is increased, which direction does the induced current flow in the wire loop?
(a) i (b) o
3. If θ is constant but B = B0 + αt, which direction does
the induced current flow? (a) i (b) o

6. i o
Loop area = A θ
Φ = BA cosθ.
If θ is increased, what is the expression for the induced voltage around the loop?
V = B cosθ dA/dt (b) V = A cosθ dB/dt
V = AB d cosθ /dt

7. A sphere of radius R is placed near a long,
straight wire that carries a steady current I.
The magnetic field generated by the current at the sphere is B. The total magnetic flux passing through the sphere is
(a) μ0 I
(b) μ0 I/(4πR2)
(c) 4πR2 μ0 I
(d) zero
(e) need more information

8. A uniform magnetic field is directed into the screen as shown below
A uniform magnetic field is directed into the screen as shown below. A loop of wire is moved to the right through this field.
Does the magnetic flux through the loop, into the screen,
increase
decrease
remain the same

9. A uniform magnetic field is directed into the screen as shown below
A uniform magnetic field is directed into the screen as shown below. A loop of wire is moved to the right through this field.
Is the direction of the induced current in the loop
clockwise
counter-clockwise
not enough information to tell
there is no induced current

10. A non-uniform magnetic field is directed into the screen as shown below. A loop of wire is moved to the right through this field.
Does the magnetic flux through the loop, into the screen,
increase
decrease
remain the same

11. A non-uniform magnetic field is directed into the screen as shown below. A loop of wire is moved to the right through this field.
Is the direction of the induced current in the loop
clockwise
counter-clockwise
not enough information to tell
there is no induced current

12. Consider a square loop made of 4 equal length conducting rods in a uniform magnetic field in to the screen
If the corners ‘a’ and ‘b’ are pulled apart, does the magnetic flux through the loop
(a) decrease (b) increase
(c) stay the same
2. Is the induced current in the loop
(a) clockwise (b) counter-clockwise
(c) there is no induced current

13. Is there an induced current in this circuit
Is there an induced current in this circuit? If so, what is its direction?
STT33.2
1. Yes, clockwise
2. Yes, counterclockwise
3. No
From Knight

14. (a) a clockwise current around the loop
A current-carrying wire is pulled away from a conducting loop in the direction shown. As the wire is moving, there is
STT33.4
(a) a clockwise current around the loop
(b) a counterclockwise current around the loop
(c) no current around the loop
From Knight

15. (a) The loop is pushed toward the top of the screen.
A conducting loop is halfway into a magnetic field. Suppose the magnetic field begins to increase rapidly in strength. What happens to the loop?
(a) The loop is pushed toward the top of the screen.
(b) The loop is pushed toward the bottom of the page.
(c) The loop is pushed to the left.
(d) The loop is pushed to the right.
(e) The tension is the wires increases but the loop
does not move.
STT33.5
From Knight

16. In the figure below, when the bar magnet is inserted into the coil, is the direction shown for induced current I
(a) correct?
(b) reversed?
(c) No current is induced in the coil.

17. As the wire loop begins to enter the field of the magnet, is the current in the loop
a) Zero
b) directed as shown
c) directed opposite to what is shown?

18. For the situation on the right, which plot best represents the magnetic flux through the loop?

19. For the situation on the right, which plot best represents the current through the loop?