Physics
Physics
Problem
A resistor and a resistor are connected in parallel. This parallel combination is then connected in series with a resistor to an ideal battery. Compute the total power drawn from the battery.Intuitive explanation
The key is to find the equivalent resistance of the entire circuit, then use that to calculate the current from the battery. Start by combining the two parallel resistors into a single equivalent resistance using the reciprocal formula—parallel resistors always have lower combined resistance than either one alone. Then add the series resistor to get the total circuit resistance, apply Ohm's law to find the current, and finally use to find the power the battery supplies.
Intuitive explanation
The key is to find the equivalent resistance of the entire circuit, then use that to calculate the current from the battery. Start by combining the two parallel resistors into a single equivalent resistance using the reciprocal formula—parallel resistors always have lower combined resistance than either one alone. Then add the series resistor to get the total circuit resistance, apply Ohm's law to find the current, and finally use to find the power the battery supplies.