"fi; .( e ).- -> e- x x x x \<., ) 4+r o. o o o

A. P. Physics Review Sheet

Name

Right Hand

Rules and

Electromagnetic

Induction

_\,

Directions:

For

each

of

the

diagrams below,

find

the direction

of

the

indicated vector quantity using your

knowledge

of

electromugr"tit-"*d

the right

hand

rules as

they

apply

to

conductors'

electric

current

(conventtnal

current)

and

magnetic fields that interact

with

them.

l.

Straight Current Carrying

Wires:

I

(

(

ii

:

-'

.

_.

_rr^.-.:-^

_i-+^

+r.a

3

A)

what

is the direction the

compass needle

points

ir*r"

";,lri'diri

in

tt

_"

wire

is

flowing

into

the

,@o

page?

, ),....-rr., ,rl

i -*1r

\'/

2

4+r

o

Wire

o btku

n

B)

what

is

the direction of the

"hft"i

in

the

wire

with

a

magnetic

field

around

it

as

indicated below?

->

e-B1

_{x x x x}

.:;,.

..-C)

lndicate the direction

of

the magnetic

field

around the cunerit carrying

wire

depicted

to

the

right.

"fi;

2.

Wire

Coils, Solenoids,

and

Electromagnets:

€

!'1''-"-l o

----A)

A wire

loop

has

a

pote.,tial difference

across

its

ends as

indicated

causing

a

iirrrent

to

flow -

_I

_l+

throughit.whatisthedirectionofthemagneticfieldatthecenteroftheloop?rr\

.(

_e

).-\__/

sl,,rL,

u

n-B)

A

loop

of

wire

(depicted

to

the

right)

has

clrli'ii,t

flowing

through

it

as indicated'

What

is

the direction of

the

magnetic

field

in the

center

of the

loop?

( '') '

\-/

c)

An

electromagnet

is

constructed as indicated

to

the

right.

which

"north"

pole?

D)

A

wire

loop

has a magnetic

field in

is

csnter directed

out

of

the

page' what

is

the

_/->^\L'

direction of the

currentL

the

loop?

rD

u!'uvr

uuvvLvu

{

_\<.,

a

)

5

end

is

its

86

_@

_{o o}

o

I

3.

Electromagnetic

lnduction, Motors,

and Generators.

A)

A

wire

is

placed in

a

magnetic

field

as

indicated

and

a

current is

caused

to flow

through the

wire

into the

page at

the moment

indicated.

What

is

the

direction of the force acting

on the

wire

at

this instant pictured?

D)

Two

conducting

rails

have a potential difference

across

them as indicated

below.

They

are centered

in

a

magnetic

field

that

is

directed

out

of

the

page.

What is the direction that

a

conducting rod

will

accelerate

in when

it

is placed

perpendicularly

across

the rails

as

indicated below?

l

S @rN

Wire

\,

B)

A

current carrying

wire

is located in

a

magnetic field that is directed

into a

the page.

whit

isthe

direction of the

forci

acting

on the

*ir"i---

----

,1|a n

*;'i'=r-i-='-

Jo--C) A

wire

is pulled

of

the

page

through the magnetic

field

depicted

to

the

right)Tn#ms

the direction of the induced current

in

the

wire

assuming

it

was-connecled

to

a

load?

abcko^

\

_Az

_t

_.r..,

€_+

N

u

E)

A

rectangular

wire

loop

with

a

certain

resistance

is pulled to

the

right

through

a

magnetic

field

as indicated. What

is

the

direction of the

flow of

electrons induced in the loop?

,

Magnetic

Field

Nanl

S

Nrt

Physics 30

M. Smith

April 201 I

Maqnetism

Ouiz

2

Multiple Choice

Identify the choice that best completes the statement or dnswers the question.

1.

Forallmagnetiosubstances,thedirectionoftheirmsgneticfieldsisdefinedasdredirectionofthe:

a.

geographic north

b,

foroe on a small test mass

4.

Ofthe following, the substanoe that will probably make the shongest magnet is:

c.

copper

d.

aluninum Name: Physics 30 M. Smith April 201 1 Narne:

c,

force on a positive test charge

/il)

force on the N-pole ofa compass

If the direction of the electron flow in the wire is from S to N, as shown in the diagram, then the comPass needle will point:

a.

north

b.

south The direction ofdre magnetic field, at point X, is toward the:

a.

bottomofthepage

q"C)teftofthepage

b.

right ofthe

page

'[

top ofthe page

3.

The diagram that best illustrates the magnetic field near a wire that carries an electron current into the plane

of

8.

The correct statement, conceming electricity and magnetism, is:

a.

electricity and magnetism are separate and rnrelated

,/blmagnetism can produce electricity and electricity can produoe magnetism

c.

electricity can produce rnagnetism, but magnetism cannot produce elecficity

d.

magnetism can produce eleotncity, but electsicity camot produce magnetism

9.

The direction ofthe magnetic force on a shaight wire,

llng

horizontally along the Eardr's magnetic equator and carrying a DC current traveling from east to west, is:

towrd

the nordr toward the south

c.

east

@

c.

do*,nward

id-'Qward

Qll

/

O

the paper is:

"./

'(D

a. b.

a.

air

,6)iron

L/

10.

A

I 5 cm metal rod, with a mass of 50 g, lies perpendicular to an external magnetic field of0.50 T. The cuffent necessary to counteract the gravitational foroe on dre rod is:

5.

_.1Qne can be sure that two steel rods are pennanently magnetized if:

fat)

one can repel the

other

c.

one can athact the other

-T: bothcantumacompass

d.

bothattractanothermagnet

6.

A method used to demonstrate the presence of a magnetic field, arouad a magnetic objeot on a laboratory table, would be to:

a.

suspend a charged balloon near the object

b.

bnng an electroscope near the object

f-g)

sprinkle iron filings near dTe object

'-f,

sprinkle larvn seed near the object

a.

0.065

A

b.

0.65

A

I

l.

The factor that does not affect the magnitude ofthe magnetic foroe on two current-carrying wires is:

@

di.e"tion ofcurrent flow through each conducting wire

--bl

_{tength of conductingwire}

c.

distance between the two conducting wires

d.

mount of current in each conducting wire

(

r( 1,t4ro

rilh

s cwcrt

{

fi*:,'*ropo*uwira

S

(

7. 2.

\ Physics 30

M. Smith

April 2011

b,

magnet X falls at a faster rate because an induced cunent in the tube creates a magnetic

z-=force

of athaction

(

c.-)magnetX falls at a slower rate beoause an induced current in the tube oreates a magnetic

'-

_{force ofrepulsion}

d.

both ma$l€ts fall at a faster rate because induced currents in both tubes create magnetic forc€s of athaction

1?. Based on the above diagram, the correct equation to determine the magnitude ofthe net force acting on magnet X as it falls through the copper tube is:

o<

"*

l4,l-

lF,l.lF-l

dr'lF,"l=

lF,l-

lr-l

18. Refer to the above diagram. As seen frorn above, the direction ofthe induced ourrent as the magnets enter the copper and glass tubes, respectively, are:

a.

no indued current- clockwise

t@

clockwise, no inducd current

5.

no induced current, counterclockwise

d.

counterclockwise, no induced ourent

19. A

bu

magnet approaches a coil of wire that is hanging freely as shown in 0re diagram below. As

it

approaches, fte coil

will

-a

Swing towards tbe magnet

(

b.)

Swing away from the magnet

'V

Remain stationary

d.

Lose heat

20. The effect seen in fte previous question can be

@lenz'sLaw

b.

Coulombs Law

c.

Olun'sLaw

d.

Telsa's Law Physics 30 M. Smith April 2011

21. An electric senerator will convert

@

Meitranicat energy to electrical energy

"bI

Mechanical energy to heat

c.

Electrical energy to mechanical energy

d.

Electrical energy to heat

e.

None ofthese

22. A charged particle is moving perpendicularly to a magn*ic field and its path is bent into a circle.

Ifthe

stength ofthe field were to double, fte speed tipled and the charged halved, the radius ofthe path

would

,

a.

Double

_{t,r ,tA ^r,,?}

b. Halve

'l' t' -

q,'4

)

c.rriple

/

_U

_U-f

,@

Be.i*

ti*es

greater

\-/

sE

-23. The charged particles in the Van Allen radiation belts (Aurora Borealis)tLost probably have been fapped there by

a.

An elecEic field

16-)

_*t

A magnetic field A scalar light fleld

d.

Agravitational field

24. When a conductor is moved through a magnetio field, the motion produces in the oonduotor a(n)

a.

Resistance

@co'."ot

o.

Electric field

d.

Magnetic field

25. A 6.00 x 10r C charged particle moving perpendicularly tkough a 2.50 x 10-3 T magnetic field has NO deflection when a 5.00 x

ld

N/C electic field is applied perpendicular to the magnetic

field.

The speed

and tvoe ofthe padicle is:

lr

il,

6t

-L

described by

/A

(

a)

2.0 x to6 rnls

't1

3.0

x l0,

m/s

c.

7.5 x l0{ m/s

d.

5.0 x 10'7 m/s

type:Gili\ornegative;

26. The figure below shows a bar moving to the left on two conducting rails, To make an induced

s

N

Nme:-_--Physics 30

M. Smith

April 20I1 12.

represents a wire, lying between two external magnets carrying an electron curreilt into the page.

Physios 30

M. Smith

Aoril 2011

l3*T1..+

2

i5.

Refer to the above diagram. A magnet is moved at uniform speed between two solenoids. The magnetio polarities at positions A and B, respectively, are:

north, north north, south c. d. south, north south, south The wiro will deflect towards the:

a.

S-pols

b.

N-pole

a.

at the north maguetic pole

b.

northward atthe equator

top ofdre page bottom ofthe page

1 3 . The vertioal antenna of a vehiole would generate the greatest induced voltage, by Earth's magnetic field,

ifthe vehiole were driven:

c.

souttrward at the equator '.td):westward _at the equator

14. Refer to the above diagram. For a simple Electric motor, a coil ofwire can be conneoted to a DC battery through a split-ring commutator. Ifcontact A is negative and contact B is positive, a:rd ifthe coil is to rotate in a clockwise direction, then the polarity ofmagnets X and Y, respectively, must be:

a.

nordr,

noih

I

_{b.J north, south}

c.

_d.

south, north_{south, south}

(

16. Based or the above diagBm, the correct observatioq conceming the demonsaation shown, is:

a.

both magrcts fall at the same rate of &ee-fall tlrough both tubes

(

i

Tua frrgmlA X ud Y, fdl tlruueh a copprr tlsa

mdt g[ua tuba

[:]

-r

I

C opptr Tubc

The rnass ofeach magnet is 80.0 g and tho length ofeach tube is 1.00 m.

F

n

Oltoe Tr.fie