Bulbs and Switches 4
The switch is closed. Compare the brightness of A before and after it is closed.
The switch is closed. Compare the brightness of A before and after it is closed.
A) Brighter before
A) Brighter before
B) No change
B) No change
C) Brighter after
C) Brighter after
Solution: C. The equivalent resistance of the circuit decreases when the switch is closed. So the current through the battery increases. This is the same current as goes through A, so it gets brighter.
Solution: C. The equivalent resistance of the circuit decreases when the switch is closed. So the current through the battery increases. This is the same current as goes through A, so it gets brighter.