Now consider what happens when a switch in the circuit is opened. Part BPart complete What happens to the brightness of bulb A? View Available Hint(s) What happens to the brightness of bulb A? It gets dimmer. It gets brighter. There is no change. SubmitPrevious Answers Correct Part C What happens to bulb C? a. It gets dimmer. b. It gets brighter. c. There is no change.

Bulb A gets dimmer

Explanation:

The figure is missing: find it in attachment.

A switch is a device that can be opened/closed in order to interrupt/allow the flow of current through a circuit.

In this case, the switch is opened: this means that the current stop flowing in the branch where the switch is located.

Looking at the figure of the circuit, this means that current will stop flowing through the branch containing the bulbs D and E, and it will continue flowing through A, B and C.

However, we notice that the overall resistance of the circuit has increased. In fact, C is in parallel with D and E: the equivalent resistance of resistors in parallel is given by

Soby removing some of the resistors in the combination, the actual equivalent resistance R increases.

This means that when opening the switch, the overall resistance of the circuit increases: and therefore, according to  Ohm's law,

where V is the voltage, R the resistance and I the current, this means that the current in the circuit will decrease (because V remains constant, since it is provided by the battery).

Therefore, the current in bulb A will also decrease, so the correct answer is

Bulb A gets dimmer