When would the bulb be brightest, in a parallel or series circuit, with the same resistance?
The correct answer and explanation is:
The bulb would be brightest in a parallel circuit.
In a parallel circuit, each component, such as a bulb, is connected directly to the power supply. This setup allows each bulb to receive the full voltage of the source. As the brightness of a bulb is determined by the power it dissipates, which is related to both the voltage and the current, having the full voltage applied to the bulb in a parallel circuit means that it operates at maximum potential, delivering the highest possible brightness.
In contrast, in a series circuit, the total voltage from the power source is divided among all the components connected in series. As a result, each bulb only receives a portion of the total voltage. This reduced voltage leads to a decrease in the current passing through each bulb. Since the brightness of the bulb is proportional to the power (which depends on the square of the current or the square of the voltage), the reduced current results in lower brightness for each bulb in a series circuit.
Additionally, in a series circuit, if more bulbs are added, the total resistance increases, further decreasing the current throughout the circuit. In a parallel circuit, however, the total resistance decreases as more bulbs are added, and each bulb still receives the full supply voltage, maintaining or even increasing its brightness.
In conclusion, the bulb in a parallel circuit will be brightest because it receives the full voltage from the power source, whereas in a series circuit, the voltage is shared, leading to dimmer bulbs.