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Determine the ratio of resistance

  • Thread starter TyErd
  • Start date
  • #1
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Homework Statement


Determine the value of the ratio R1/R2

sorry guys I forgot to write the values in, V1=0, V2=2.4V and A=10.8A


Homework Equations


V=IR


The Attempt at a Solution


I found thecurrent through R2 to be 6mA and then calculated resistance by doing 2.4/6mA=400ohms. Then i got stuck.
 

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Answers and Replies

  • #2
phyzguy
Science Advisor
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How could you possibly have calculated 6 mA unless you know V1, V2, and A? I think the problem is asking for R1/R2 in terms of V1, V2, and A.
 
  • #3
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The only way we could assume the potential drop across V1 and V2 is to know the colour of the LED...but we don't have that.

If you have the equation R=V/I then you can form equations for each resistor R1 and R2; if you are aiming for higher grades (>=A) at college level you should know how to form ratios of equations.
 
  • #4
299
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Sorry guys I forgot to add the values in. My mistake. I've added the values in just then.
 

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