For the circuit shown all wires have negligible resistance

Last updated: 6/11/2023

For the circuit shown all wires have negligible resistance the battery has a constant internal resistance of r 8 092 and the two light bulbs B and B are identical each with resistance Rbulb The variable resistor is initially set R 26 092 The switch S in the circuit now is closed To what resistance must the variable resistor be set if bulb B is to have the same brightness after the switch is closed as it did with the switch open www R Battery B 09 09 O 13 09 O 16 09 The answer can be computed only if the bulbs resistance Rhulh is known