Question

What is the resistance of a resistor if the potential difference across the resistor is 4.0 V when a current of 10.0 A flows through the resistor?

Answer 1

@beccaboo333

Answer 2

@hartnn

Answer 3

Use Ohm's Law.
\[V = IR\]

Answer 4

Where 'R' is the resistance, V is the voltage (Volts), and I is the current (amperes).

Answer 5

Okay so R = 4.0 x 10.0 ?

Answer 6

No, solve for R first. What would you have to do to solve for R.

Answer 7

I honestly have no idea...

Answer 8

It's basically algebra. Solve for R. It's being multiplied by 'I'. So, to undo multiplication, we would have to divide. Divide both sides by I.
\[R = \frac{V}{I}\]

Answer 9

Oh okay so R = 4.0/ 10.0 ??

Answer 10

yes

Answer 11

This is why you need the really thick wires in your extension cord if you're running power to something that draws a large current! Even a small resistance will cause an appreciable voltage drop when enough current flows.