A2L Item 223

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?

  1. Increases
  2. Decreases
  3. Stays the same
  4. Bulb goes out
  5. Can’t determine



(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.