Comparing Light Bulbs in a Lab Experiment

Two light bulbs are being used in a lab experiment with a single battery. Bulb A has half the resistance as Bulb B. Which bulb is the dimmest in series? Which bulb is the brightest in parallel? Explain.

Answer and Explanation:

It is given that bulb A has the half the resistance as B

WHEN THEY ARE CONNECTED IN SERIES:
In a series circuit, we know that current is the same in the whole circuit. The power is given by P = i^2R. From the expression, it is clear that the bulb which has more resistance consumes more power as the current is the same. The bulb that consumes more power will be the brightest.
It is given that the resistance of bulb A is half the resistance of B. So, bulb A will be the dimmest in this case.

WHEN THEY ARE CONNECTED IN PARALLEL:
In a parallel circuit, the voltage is the same across the circuit. The power is given by P = V^2/R. From the expression, it is clear that the bulb which has the least resistance will consume more power and thus will be the brightest. As the resistance of bulb A is less, it will be the brightest in this case.

Two light bulbs are being used in a lab experiment with a single battery. Bulb A has half the resistance as Bulb B. Which bulb is the dimmest in series? Which bulb is the brightest in parallel? Explain.

It is given that bulb A has the half the resistance as B. When they are connected in series, bulb A will be the dimmest as it has less resistance. When they are connected in parallel, bulb A will be the brightest as it has the least resistance and consumes more power in a parallel circuit.