1. For the wire carrying a flow of electrons in the direction shown, is the magnetic field at point P - P (a)to the right (b)to the left (c)up (d)into the screen (e)out of the screen

2. In the figure below, which is the direction of the magnetic field at point… 1)…P?2) …Q?3)…R? In the figure above, where is the magnetic field the weakest? (a) point P (b) point Q (c) point R

3. The magnetic field at P due to the current I in Is directed (a) into the screen(b) out of the screen (c) up (d) down (e) zero P

4. The magnitude of the magnetic field contribution from the current element above is

5. The total magnetic field at P from the current in the wire shown on the right is:

6. The Biot-Savart law for the contribution to the magnetic field from a current element is given on the right. I) Is the ‘r’ given by (a) r 1 (b) r 2 (c) r 3 ? II) Is the 2 given by (a) 2 1 (b) 2 2 (c) 2 3 ? III) Is the direction of at P (a) up (b) down (c)into page (d)out of page Use the figure to answer the following questions about the Biot-Savart Law

7. Magnetic field from a section of a straight wire The magnitude of the magnetic field at P due to the current I in is

8. Magnetic field from a section of a straight wire Given the equation and figure on the right, what is the field at P due to an infinitely long wire carrying current I?

9. The magnetic field at a distance “a” from a straight wire carrying current I is given in Figure 1. Therefore, the field at point P in Figure 2 is: Figure 1Figure 2

12. For the two long wires on the right, the vector magnetic field at P is best represented by where...

13. Two wires carry equal currents I 1 into the screen, each producing a magnetic field B 1 at point P The total field at P is given by

14. Magnetic field on the axis of a circular turn of wire 1. Which best represents the field at P from i) and ii) ? (a)(b)(c)(d)(e) 2. Which best represents the total field at P? (a)(b)(c)(d)(e)

15. Which of the following is the equation for the magnetic field on the axis of a solenoid? Magnetic field on the axis of a solenoid

16. 1. Is the field at P 1 directed (a) to the right (b) to the left (c) neither 2. Near the centre of a long solenoid, is 3. Near one end of a long solenoid, is

17. Three equations from the formula sheet are given below for the magnetic field caused by a current I. Which of these is the correct one to use for the magnetic field… 1. …at a given distance from a straight wire 2. …on the axis of a circular turn 3. …on the axis of a solenoid (coil) (c) (a)(b)

18. Assuming B= 0 just outside the coil, use Ampere's law and the dotted path provided to determine the field B on the axis of the coil. Current I flows in the coil on the right Ampere's law:

19. Current I flows in the coil on the right Ampere's law: (b) Sketch the shape and direction of the magnetic field near a turn adjacent to the one in (a). (c) Do the fields in (a) and (b) add or subtract along the axis of the coil? (d) Do these fields in (a) and (b) add or subtract in the region between two adjacent wires? (e) Draw a magnetic field line just inside the line of wires on the bottom of the coil. Redraw the coil on your page, and (a) Sketch the shape and direction of the magnetic field near one of the wire turns at the bottom.

20. Current I flows in the coil on the right Ampere's law: (2) Does the field in (a) reinforce or cancel the corresponding field from a turn at the bottom of the coil? Inside the coil: (a) reinforce(b) cancel Outside the coil: (a) reinforce(b) cancel (3) From our discussion to date, sketch a few field lines around and inside the whole coil. Remember that the field lines are closest together where B is strongest. Redraw the coil on your page, and (1) Sketch the shape and direction of the magnetic field near one of the wire turns at the top.

21. Ampere's law: The magnetic field lines around a solenoid look roughly as sketched on the right To calculate B on the axis of the solenoid, select a closed path, containing some current and consisting of several segments, such that for each segment either (i) B ~ 0, or (ii) z path, or (iii) B ~ constant and path. Either (b) or (c) (d)

22. Ampere's law: A large wire of radius R carries a current I 0 into the screen as sketched on the right. The current is uniformly distributed over the wire. Ampère's law is used to determine the magnetic field strength B at a distance r from the centre of the wire. 1. For the dashed path, how much current is I enclosed ? (a) I 0 (b) (c) (d) 2. At point P, is : (a) B ds (b) zero (c) can't tell? 3. Which is the correct result for B(r) from Ampère's law? (a) (b) (c) (d) (e)

24. - into screen What is the direction of the force on the particle? (a)into screen (b) out of screen(c) up (d) down (e) to right Does the particle rotate (a) clockwise?(b) counterclockwise?

25. For a charged particle moving with velocity in a circle in a magnetic field, which of the following is most correct? (a) (b) (c) (d) (e) a, b and c Which of the following is the correct angular velocity of a particle of charge q moving perpendicular to a magnetic field B? (a) (b)(c) (d) (e)

26. What is the direction of the magnetic force on the negative particle q below, caused by the magnetic field from the wire? a)Up b)Down c)Into screen d)Out of screen

27. (From pre-class quiz) Distribution of charge in a current sheet, in a magnetic field A steady conventional current, I, is flowing northward in a horizontal conducting sheet, and a magnetic field is oriented downwards through the sheet. Which of the following statements is true? a. The East edge of the sheet will carry no net charge. b. The East edge of the sheet is positively charged. c. The East edge of the sheet is negatively charged. d. Both the East and the West edges of the sheet are positively charged.

28. 1. Which side of the metal ribbon shown on the right is positive? (a) a (b) b (c) c (d) d 2. What direction is the electric field in the ribbon, caused by the magnetic field?

31. The charge carriers in the wire are electrons. What is the direction of the magnetic force on the wire? (a) out of the page(b) up (c) down(d) to right (e) to left

32. Two long wires carry current into the screen. 1. What is the direction of the magnetic field at B caused by A? (a) to the right (b) to the left (c) up (d) down 2. Is the direction of the force on B (a) up (b) down (c) into screen (d) out of screen (e) to the left 3. Do the two wires (a) attract each other (b) repel each other (c) neither

33. Two long parallel wires carry currents, I 1 into the screen and I 2 > I 1 out of the screen. 1. What is the direction of the force on i) wire #1? ii) wire #2? 2. Compared to the force on wire #1, the force on #2 is (a) greater(b) smaller(c) the same? 3. What entirely independent method could you use to determine the direction in question 1. ii) given the answer in 1. i)?

34. 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

35. 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

36. What is for this current loop?

37. A rectangular loop of wire carries a current I in a magnetic field Which of the following gives the force on one side of the loop?

38. A rectangular loop of wire carries a current I in a magnetic field In which direction does the coil rotate (direction of angular velocity )? N S

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

40. If the current flows through the galvanometer coil in the direction of the bold arrows, does the pointer P deflect ? (a) clockwise (b) counterclockwise (c) not enough information to tell The Galvanometer