A battery, emf of 2.0V, of internal resistance 1.0 ohms, is connected to an external resistor R. A voltmeter is connected across the terminals of R. When the switch is closed, the reading on the voltmeter is 1.6V. Calculate the value of R.
So I worked out that the value of lost volts is 0.4V, and divided this by 1.0 ohms to calculate the current as 0.4A.
So to calculate R, I did 1.6 / 0.4 = 4.0ohms.
Is this correct?
This is what the diagram of the circuit looks like if that helps/
rearrange for R
= (2/0.4) -1