Final answer:
Adding another light bulb in a series circuit decreases the current, increases the resistance, and decreases the brightness of the light bulbs.
Step-by-step explanation:
In a series circuit with two light bulbs, adding another light bulb will affect the current, resistance, and brightness of the light bulbs.
a) Current: When another light bulb is added, the total current in the circuit decreases. This is because the total resistance increases with the addition of another bulb, resulting in a reduced flow of current.
b) Resistance: Adding another light bulb increases the total resistance in the circuit. Each bulb in a series circuit adds to the overall resistance, causing the resistance to go up.
c) Brightness of the light bulbs: Adding another bulb increases the resistance in the circuit, which in turn decreases the flow of current. As a result, each bulb receives less current and the brightness of all the bulbs decreases.
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