Determine the ratio of resistance

  • Thread starter TyErd
  • Start date
  • #1
299
0

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.
 

Attachments

  • circuit8.JPG
    circuit8.JPG
    9.7 KB · Views: 369
Last edited:

Answers and Replies

  • #2
phyzguy
Science Advisor
5,009
1,994


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
69
0


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
0


Sorry guys I forgot to add the values in. My mistake. I've added the values in just then.
 

Related Threads on Determine the ratio of resistance

Replies
4
Views
2K
  • Last Post
Replies
2
Views
1K
Replies
2
Views
2K
Replies
5
Views
2K
V
Replies
6
Views
9K
  • Last Post
Replies
22
Views
5K
Replies
6
Views
1K
  • Last Post
Replies
1
Views
786
  • Last Post
Replies
7
Views
753
  • Last Post
Replies
8
Views
5K
Top