Slide 1 / 25

1 A particle of charge +q enters a uniform magnetic field B directed into the page. The direction of the magnetic force FB on the particle is

A top of the page

B bottom of the page

C Left

D Right

E out of the page

Slide 2 / 25

2 A particle of charge -q enters a uniform magnetic field B directed out of the page. The direction of the magnetic force FB on the particle is

A top of the page

B bottom of the page

C Left

D Right

E out of the page

Slide 3 / 25

3 A particle of charge -q enters a uniform magnetic field B directed out of the page. The direction of the magnetic force FB on the particle is

A top of the page

B bottom of the page

C Left

D Right

E no force applied

Slide 4 / 25

4 A charge particle -q enters a uniform magnetic field B. If FB is the magnetic force, which of the following represents the particle's velocity?

A qB/FB

B q/FBB

C FB/qB

D 1/qFBB

E B/qFB

Slide 5 / 25

5 A current carrying wire carries a current into the page. The wire is placed in a uniform magnetic field directed to the right. The magnetic force on the current is directed

A top of the page

B bottom of the page

C left

D right

E into the page

Slide 6 / 25

6 A current carrying wire of length L and mass m is placed in a uniform magnetic field B. The current in the wire is I. What must the direction of the field be in order to balance the gravity?

A into the page

B bottom of the page

C right

D left

E out of the page

Slide 7 / 25

7 A current carrying wire of length L and mass m is placed in a uniform magnetic field. The current in the wire is I. What must the magnitude of the field be in order to balance the gravity?

A mg/IL

B mL/Ig

C Ig/gL

D Ig/mL

E Il/mg

Slide 8 / 25

8 A positive charges travels through a uniform magnetic field. The diagram represents the direction of the particle’s velocity and magnetic force on it at the certain point. What is the direction of the magnetic field B?

A out of the page

B into the page

C right

D left

E top of the page

Slide 9 / 25

Slide 10 / 25

10 A negatively charged particle of charge q and mass m moves with constant speed v in a circular path in the presence of a uniform field B. Which of following represents the radius r of the moving charge?

A qB/mv

B qv/mB

C mB/qv

D qBm/v

E mv/qB

Slide 11 / 25

11 An electron enters a region where both a magnetic field B into the page and electric field E between the two plates act on the particle as shown below. What must be the direction of the electric field in order for the particle to move in the straight line?

A top of the page

B bottom of the page

C Left

D Right

E into the page

Slide 12 / 25

12 An electron enters a region where both a magnetic field B into the page and electric field E between the two plates act on the particle as shown above. Which of the following represents the particle’s velocity when it passes through the region of two fields undeflected?

A E/B

B B/E

C B2/E

D B/

E E2/B

Slide 13 / 25

13 An electron enters a region where both a magnetic field B into the page and electric field E between the two plates act on the particle as shown above. If the electric field is removed which of the following represents the motion of the electron?

A To the right

B Parabolic path downward

C Parabolic path upward

D Circular path clockwise

E Circular path counter clockwise

Slide 14 / 25

14 An electric current flows in a closed loop made of two fixed rails, power supply, and very light rod that is free to move on the top of the rails. A uniform magnetic field is perpendicular to the plane of the circuit. What is the direction of magnetic force on the rod?

A +y

B -y

C -x

D +x

E +z

Slide 15 / 25

15 An electric current flows in a closed loop made of two fixed rails, power supply, and very light rod of length L that is free to move on the top of the rails. A uniform magnetic field B is perpendicular to the plane of the circuit. If current source supplies voltage V and net resistance R, what is the magnitude of the magnetic force on the rod?

A VBL/R

B VB/RL

C BL/VR

D VL/BR

E VR/BL

Slide 16 / 25

16 A rectangular piece of metal is placed in a uniform magnetic field and connected to a battery on two opposite sides. Which one of the following statements is incorrect?

A The conventional current in the metal plate is directed from the left to the right

B The flow of electrons passes the metal plate from the right to the left

C Point L has higher potential than point N

D Point N has higher potential that point L

E The potential difference between point L and N is explained by Hall Effect

Slide 17 / 25

17 An electric current flows straight up. An electron approaches the current from East. What is the direction of the magnetic force on the electron due to the current?

A East

B West

C North

D South

E Up

Slide 18 / 25

18 A positively charged particle moves in the region of an electric current placed below the particle. What is the direction of magnetic force on the charge?

A Top of the page

B Bottom of the page

C Left

D Right

E Out of the page

Slide 19 / 25

19 A uniform magnetic field B is parallel to the xy-plane and in the +y-direction, as shown above. A positively charged particle initially moves with velocity v in the xy-plane at an angle Ɵ to the magnetic field and the y-axis. Which of the following paths will the particle follow in the presence of the magnetic field?

A Continue a straight-line path

B A circular path in the xy-plane

C A circular path in the yz-plane

D A helical path with its axis parallel to the y-axis

E A helical path with its axis parallel to the z-axis

Slide 20 / 25

20 A uniform magnetic field B is parallel to the xy-plane and in the +y-direction, as shown above. A positively charged particle q initially moves with velocity v in the xy-plane at an angle Ɵ to the magnetic field and the y-axis. What is the magnitude of the force acting on the charge?

A qvB

B qvB cosƟ

C qvB sinƟ

D qv/BsinƟ

E qvB tanƟ

Slide 21 / 25

21 A proton moves parallel to the x-axis in the positive x-direction. What must the direction of the electric field be in order to keep the proton going undeflected if the magnetic field is established in +y direction?

A Positive y-direction

B Postitive z-direction

C Negative x-direction

D Negative y-direction

E Negative z-direction

Slide 22 / 25

22 A current-carrying loop of wire is placed in a uniform magnetic field perpendicular to the plane of the loop. Under the influence of the magnetic force the loop will

A rotate with respect to its center

B rotate with respect to its diameter

C contract

D expand

E stays stationary

Slide 23 / 25

23 A bar magnet and a wire loop carrying current I are arranged as shown below. What is the direction of the force on the current loop due to the magnet?

A Toward the magnet

B Away from the magnet

C Toward the top of the page

D Toward the bottom of the page

E There is no force on the current loop

Slide 24 / 25

24 A charged particle in a uniform magnetic field B moves in a circular path of radius r. Which of the following represents the frequency of revolution f?

A qB/2πm

B qm/2πB

C 2πB/qm

D qBm/2π

E qm/2πB

Slide 25 / 25

25 A loop of wire has a current I running through it in a counter clockwise direction. An electron moving with velocity v downward is placed outside of the loop and in the plane of the loop. Which of the following represents the direction of the magnetic force due to the loop on the electron?

A To the right

B To the left

C Into the page

D Out of the page

E To the top of the page