Final answer:
Doubling the number of batteries in a circuit leads to both the voltage and current doubling.
Step-by-step explanation:
If you double the number of batteries in a circuit, both the voltage and current double. This is because the voltage produced by each battery remains the same, but the total voltage across the circuit increases. Similarly, the total current flowing through the circuit increases since the current provided by each battery adds up.
For example, if a single battery produces a voltage of 1.5 volts and a current of 1 ampere, when you double the number of batteries, the voltage across the circuit would be 3 volts and the current would be 2 amperes.
Learn more about Effects of doubling the number of batteries in a circuit