Goal: Hone understanding of parallel circuits.
Source: 283-570 lights in parallel
A light bulb is connected to a battery as shown in Figure A below. When
a second bulb is connected as shown in Figure B, what happens to the
brightness of the original bulb?
- Increases
- Decreases
- Stays the same
- Bulb goes out
- Can’t determine
Commentary:
Answer
(3) If the battery cannot sustain the potential difference the bulb will
dim somewhat. This can confuse students so any demonstration should not
use a marginal battery.