A very long wire lies in a plane with a short wire segment. The long wire carries current I, while the short wire of length L carries current i. The two wires are parallel to each other. Which of the following statements are true?
A. The direction of the magnetic force exerted by the long wire on the short wire is directed away from the long wire.
B. The magnitude of the force on the short wire is 0IiL/2d.
C. The long wire experiences a force of exactly the same magnitude as the force experienced by the short wire.
1.A only
2.B only
3.C only
4.A and B
5.A and C
6.B and C
7.A, B, and C
8.None of them are true
[Ques. 2] Consider a long thin straight wire with a current I. Which of the following statements about the magnetic field lines is true?
A. Field lines are parallel to the wire.
B. Field lines are perpendicular to the wire.
C. Field lines are directed radially away from the wire.
D. Field lines are circles centered on any point on the wire.
1.A only
2.B only
3.C only
4.D only
5.A and C only
6.B and D only
7.B and C only
8.None of them is true.
[Ques. 3] A charge has an initial velocity parallel to the y-axis in E and B fields. Both fields point along the x axis. Which of the following statements regarding the charge's motion are correct?
1.The charge will travel along a straight-line path.
2.The charge's speed will change as it travels.
3.The charge will travel in a helical path.
4.The charge will travel in a helical path of increasing pitch.
5.The charge will travel in a circle in the x-y plane.
6.1 and 2 only
7.2 and 4 only
8.None of the above
[Ques. 4] A charge is released from rest in E and B fields. Both fields point along the x axis. Which of the following statements regarding the charge's motion are correct?<--EndFragment--> y after the switch is closed?
1.The charge will travel along a straight-line path.
2.The charge's speed will change as it travels.
3.The charge will travel in a helical path.
4.The charge will travel in a helical path of increasing pitch.
5.The charge will travel in a circle in the x-y plane.
6.1 and 2 only
7.2 and 4 only
8.None of the above
[Ques. 5] A charged particle moves into a region containing both an electric field and a magnetic field. Which of the statements below is/are true?
A. The particle cannot accelerate in the direction of B.
B. The path of the particle must be a circle.
C. Any change in the particle's kinetic energy is caused by the E field.
1.Only A
2.Only B
3.Only C
4.Both A and B
5.Both A and C
6.Both B and C
7.All are true.
8.None are true.
[Ques. 6] Two identical bar magnets are placed rigidly and anti-parallel to each other as shown. At what locations, if any, is the net magnetic field close to zero?
1.A only
2.B only
3.C only
4.D only
5.A and B
6.A, B, and C
7.C and D
8.None of the above.
[Ques. 7] A bar magnet moving with speed V passes below a stationary charge q. What can be said about the magnitude of the magnetic forces on the bar magnet (Fb) and on the charge q (Fq).
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