A 20-ohm resistor is connected to a 10 V battery. The 20-ohm resistor is replaced with a smaller resistor. What happens to the voltage across the resistor?

Explanation:

It is given that,

Resistance, R = 20 ohms

Voltage of the battery, V = 10 V

We can find current flowing through the circuit using Ohm's law as follows :

V = IR

\begin{gathered}I=\dfrac{V}{R}I=\dfrac{10}{20}I=0.5\ A\end{gathered}I=RVI=2010I=0.5 A

It can be seen from the Ohm's law, that the current is directly proportional to the voltage. It means that if the battery is replaced by a battery that provides a larger voltage, the current through the circuit will be more than 0.5 A i.e. it increases