calculating voltage across resistors

[ingram010]

Hi all,

I am looking for a formula to work out the following-


500v---/\/\/\/\/---X---/\/\/\/\/---0v
1megohm 10kohm

what is X?

cheers

[denverdoc]

Welcome to PF. Its not clear at least to me what the problem is, is X an unknown voltage. If so
use V=iR first compute i using the total series resistance (here the sum of 1Mohm and 10Kohm.
Then V is just the i*the resistance over which you want to find voltage.

or all in one v=500*R/(R+r) This is just voltage divider eqn. Thats the voltage across the first resistance, voltage across the second would be:

500*r/(R+r), if your looking for the value of x, this would be the one to use.

[ingram010]

Hi, on reflection it isnt very clear. Sorry.


how about this-

500v---\/\R1\/\----X----\/\R2\/\---0v

If R1 = 1Mohm and R2 = 10Kohm
what is the voltage at X?

Or this one -

500v---\/\R1\/\--X--\/\R2\/\--Y--\/\R3\/\--Z--\/\R4\/\---0v

If R1 = 1Mohm, R2 = 10Kohm, R3 = 10Kohm and R4 = 10Kohm
what is the voltage at X,Y and Z?

is there a simple calculation for this problem?

[DAKONG]

first find the electric current
then use Ohm's law
V=IR
500=I(106+103)
I = ?
:grumpy: 1
V = IR
X - 0 = I(R2)

:grumpy: 2
V = IR
500 - X = I(R1)