Short answerEasy1 mark
8(iii)
Three identical bulbs B1, B2 and B3 each of power rating 18 W, 12 V are connected to a battery of 12 V.
If the bulb B3 is removed from the circuit, then will the brightness of the bulb B1 increase, decrease or remain the same?
Topic: Effect of circuit change on bulb brightness
Question wording verified against source paper
Answer
Exam answer
Brightness of B₁ decreases.
Explanation
Removing B₃ makes B₁ and B₂ series: total resistance rises from 12 Ω to 16 Ω, so current through B₁ decreases.
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