Physics prob.

[MikeMike]

Two resistors, 36 and 69 Ohms, are connected in paralel. The current flowing through the 69-Ohms resistor is 1.9A.

Determine the current in the other resistor.

how do i do this?? i cant seem to find an equation in the book. it seems like i should figure out the voltage but that was wrong.

 

[FriedPixel]

I'm not completely sure of this, but this is how I would go about it:

Use Ohm's Law, E=IR
Find E using the 69Ohm and the 1.9A. E = 131.1V
Use that value to find I on the other one. I = 131.1/36 = 3.64A

 

[MikeMike]

Originally posted by: FriedPixel
I'm not completely sure of this, but this is how I would go about it:

Use Ohm's Law, E=IR
Find E using the 69Ohm and the 1.9A. E = 131.1V
Use that value to find I on the other one. I = 131.1/36 = 3.64A

that answers wrong

 

[00obrimw]

FriedPixel's answer seems right to me.

 

[jonessoda]

V=IR

for parallel resistors: 1/R(total) = 1/R(1) + 1/R(2) +...+1/R(N)

 

[Heisenberg]

Originally posted by: FriedPixel
I'm not completely sure of this, but this is how I would go about it:

Use Ohm's Law, E=IR
Find E using the 69Ohm and the 1.9A. E = 131.1V
Use that value to find I on the other one. I = 131.1/36 = 3.64A

That answer seems right. The voltage is always the same across resistors in parallel while the current is different. In series, it's the opposite.

 

[Fenixgoon]

Originally posted by: MIKEMIKE

Originally posted by: FriedPixel
I'm not completely sure of this, but this is how I would go about it:

Use Ohm's Law, E=IR
Find E using the 69Ohm and the 1.9A. E = 131.1V
Use that value to find I on the other one. I = 131.1/36 = 3.64A

that answers wrong

isnt voltage constant in a parallel circuit though, or is it current? i hate E&M for a reason 🙂

 

[hypn0tik]

Originally posted by: FriedPixel
I'm not completely sure of this, but this is how I would go about it:

Use Ohm's Law, E=IR
Find E using the 69Ohm and the 1.9A. E = 131.1V
Use that value to find I on the other one. I = 131.1/36 = 3.64A

Looks right to me.

Edit: What's the answer in the book?

 

[jai6638]

The answer is correct imo since the current changes in parallel with the voltage remains the same