section 16.4 force on current-carrying conductor in magnetic field

8/14/2019 Section 16.4 Force on Current-carrying Conductor in Magnetic Field

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Manhattan Press (H.K.) Ltd. 1

Section 16.4Section 16.4

Force on current-carryingForce on current-carrying

conductor in magnetic fieldconductor in magnetic field

Section 16.4Section 16.4

Force on current-carryingForce on current-carrying

conductor in magnetic fieldconductor in magnetic field

Factors affecting the magnitudeFactors affecting the magnitude

of force on current-carrying conductorof force on current-carrying conductor

Fleming's left-hand ruleFleming's left-hand rule

Turning effect of coilTurning effect of coil


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Force on current-carrying conductor

in magnetic field

current-carrying conductorexperiences force

in magnetic field

16.4 Force on current-carrying conductor in magnetic field (SB p. 120)

Go to

Discussion 5Discussion 5


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Expt. 16D

Magnetic force

on a current-

carrying

conductor


in magnetic field


d.c. power supply

magnet

rider

Fleming's apparatus
http://movie/Expt%2016D/16D.avi


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eitherdirection ofcurrent


in magnetic field


poles of magnet

reversed

moves in opposite

direction


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Fleming's left-hand rule


field

force

current



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current

force

field

current



CAL

Workshop 1

Force on

current-

carrying

conductor in

magnetic field
http://cal/E-SimPhy_406.exe


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magnetic forceby

(1) Use stronger magnet

Factors affecting the magnitude of

force on current-carrying conductor


(2)no. of turns of wire

(3)current

current


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Turning effect of coil

turning effect

principle ofmotors & meters


Thinking 6Thinking 6

field

current

force


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Example 2:Example 2:A conducting rod is placed in each of the following open

circuits. State the motion of the conducting rod.

Solut

ion


(a) (b)

To the right. To the left.


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Example 2: (Cont)Example 2: (Cont)

Solut

ion


(c) (d)

To the right. At rest.


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Class Practice 3:Class Practice 3:A copper rod is placed on an open circuit. When the switch

is closed and the resistance of the rheostat is increased

gradually, state and explain the motion of the rod when it is

placed at positions AB and CD.


magnetic

field region

Ans

wer


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Class Practice 3:Class Practice 3:At AB,

At CD,Ans

wer

the rod does not move because there is

no magnetic field around it.


the rod moves to the right according to

Fleming's left hand rule. It moves at a decreasing

acceleration because the current is decreasing.

magnetic

field

region

Thinking 7Thinking 7 Thinking 8Thinking 8


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To section 16.5
http://e-ch16_05.ppt/http://e-ch16_05.ppt/


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Discussion 5:Discussion 5:

What happens when a current-carrying conductoris placed in a magnetic field? Discuss with your

classmates.

(Hint: A magnet experiences a force near another

magnet.)

The current-carrying conductor experiences a force in

a magnetic field.

Ans

wer

Return to

TextText



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The figure shows three long current-carrying

straight wires P, Q and R. The magnitude ofthe current flowing through each wire is the

same. Draw a diagram to represent the

direction of the resultant force acting onP

.

Ans

wer



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Thinking 6 (Cont)Thinking 6 (Cont)

Return to

TextText



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In Class Practice 3, if both the directions of themagnetic field and the terminals of the cell are

reversed, does the motion of the rod at

positionsAB

andCD

change?Ans

wer


Return to

TextText

At AB, the rod still does not move.

At CD, the rod still moves to the right.

magnetic

field

region


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When lightning strikes, negative charges flow froma cloud to the ground. Explain why

the strike is deflected to the west.

AnswerThe downward flow of negativecharges in a lightning strike is

equivalent to an upward flow of current. With the

earth's magnetic field pointing from the south to

the north, by Fleming's left hand rule, thenegative charges in the lightning strike would

be deflected towards the west, except at the

Arctic and the Antarctic of the earth.

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TextText


section 16.4 force on current-carrying conductor in magnetic field

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