Resistance of a wire

  • Thread starter john216
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  • #1
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Homework Statement




Suppose that a 32-meter length of resistive wire is connected across the terminals of a battery. If a voltmeter reads 21 V when connected across the battery terminals, what should it read when connected across a 18-meter section of the wire? Enter you answers using one decimal place, do not enter units.



Homework Equations



e = iR


The Attempt at a Solution



thought the voltage doesn't change.
but I think its wrong. Please help?
 

Answers and Replies

  • #2
SammyS
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Homework Statement



Suppose that a 32-meter length of resistive wire is connected across the terminals of a battery. If a voltmeter reads 21 V when connected across the battery terminals, what should it read when connected across a 18-meter section of the wire? Enter you answers using one decimal place, do not enter units.

Homework Equations



e = iR

The Attempt at a Solution



thought the voltage doesn't change.
but I think its wrong. Please help?
Hello john216. Welcome to PF !

Think of this as 32 one-meter lengths of wire connected in series.

What is the voltage drop across any one of those one-meter wires ?

How much across 18 of them ?
 
  • #3
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could you clarify little?
i'm confused
 
  • #4
SammyS
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could you clarify little?
I'm confused
It's hard for me to know what part/parts of what I posted confuses you.

What do you understand about series circuits and resistances in series?

What do you understand about voltage drop and Ohm's Law?

etc.
 

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