AP Physics 1 Question 278: Answer and Explanation
Use your browser's back button to return to your test results.
5. Three identical light bulbs are connected to a source of emf, as shown in the diagram above. What will happen if the middle bulb burns out?
- A. The light intensity of the other two bulbs will decrease (but they won't go out).
- B. The light intensity of the other two bulbs will increase.
- C. The light intensity of the other two bulbs will remain the same.
- D. More current will be drawn from the source of emf.
Correct Answer: C
If each of the identical bulbs has resistance R, then the current through each bulb is ε/R. This is unchanged if the middle branch is taken out of the parallel circuit. (What will change is the total amount of current provided by the battery.)