What happens to the brightness of the remaining bulbs after unscrewing a bulb in a combined circuit, according to the source?

What happens to the brightness of the remaining bulbs after unscrewing a bulb in a combined circuit, according to the source?

• A. The remaining bulbs’ brightness changes unpredictably
• B. Only the unscrewed bulb changes brightness
• C. One disappears completely while the other stays as is
• D. One dims and the other brightens depending on arrangement

Answer: (D)

Brightness depends on how much current flows through each bulb and the voltage it actually receives. In a combined circuit, bulbs don’t all share the same path in the same way, so unscrewing one changes how current is distributed among the remaining bulbs. If the power source isn’t ideal and has some internal resistance, removing a bulb reduces the total current drawn, which can raise the voltage across the remaining bulbs. That extra voltage can make one bulb brighter while another, sharing a different part of the circuit, might dim because its current is reduced. Because the exact outcome hinges on how the bulbs are connected, you can end up with one dimmer and the other brighter depending on the arrangement.

Brightness depends on how much current flows through each bulb and the voltage it actually receives. In a combined circuit, bulbs don’t all share the same path in the same way, so unscrewing one changes how current is distributed among the remaining bulbs. If the power source isn’t ideal and has some internal resistance, removing a bulb reduces the total current drawn, which can raise the voltage across the remaining bulbs. That extra voltage can make one bulb brighter while another, sharing a different part of the circuit, might dim because its current is reduced. Because the exact outcome hinges on how the bulbs are connected, you can end up with one dimmer and the other brighter depending on the arrangement.