Question

A battery is labeled with a voltage of 9 volts. When the battery is connected to a resistor, the current is 1.2 amp and a digital voltmeter placed across the battery measures 8.0 volts. What is the internal resistance of the battery?

Answer 1

Answer:

0.833 ohm

Explanation:

We have given the labeled voltage that is terminal voltage V =9 volt

The current through the battery is 1.2 A

The emf of the battery that is E =8 volt

For any battery we know that $V=E+iR$

Where V is terminal voltage , E is EMF and R is internal resistance

So $9=8+1.2\times R$

$R=\frac{1}{1.2}=0.833ohm$