Final answer:
In a series circuit, when a light bulb is removed, the other bulb gets brighter because the resistance in the circuit decreases and more current flows through it.
Step-by-step explanation:
In a series circuit, the components are connected one after another, so the current that flows through them is the same. When a light bulb is removed from its socket in a series circuit, the resistance in the circuit decreases, causing more current to flow through the other bulb. This increased current makes the remaining bulb brighter.