# Thread: Ohms Law equation - Help please, I don't get it

1. ## Ohms Law equation - Help please, I don't get it

Is anybody able to help me with the following:

Calculate the magnitude of the current I when a voltage of 100 V is applied across a resistance R of 10^12 (Ohms law).

I don't even know where I'm meant to start, or how I'm meant to work this out.

2. Originally Posted by AJShaw
Is anybody able to help me with the following:

Calculate the magnitude of the current I when a voltage of 100 V is applied across a resistance R of 10^12 (Ohms law).

I don't even know where I'm meant to start, or how I'm meant to work this out.
Substitute into V = IR. Solve for I (use a basic index law).

3. v = IR

I = 100v/10^12

I = 1 x 10^-10

Is this right? If it is wrong, can you show me step by step how to work it out, please?

4. Originally Posted by AJShaw
v = IR

I = 100v/10^12

I = 1 x 10^-10

Is this right? [snip]
Yes. (Except that the answer should have a unit. When working in V and Ohms the unit of current is Amp).

5. Thank-you so much