Circuits in Series and Parallel (1) (2) - Saved to this PC View Help Tell me wha
ID: 2303775 • Letter: C
Question
Circuits in Series and Parallel (1) (2) - Saved to this PC View Help Tell me what you want to do es Mailings Review Aa - Tith Heading 2 |?-12-?· 11Norma?No Spac Heading 1 ? ·A-? Styles Paragraph 7.(1 point) A circuit contains a battery, a switch, and two light bulbs which serve as sources of resistance (see figure to the right). The switch is initially open. When the switch is closed, how will the brightness of bulb D compare to that of bulb E? a. Bulb D will be brighter than Bulb E b. Bulb D will be dimmer than Bulb E c. Both bulbs will be the same brightness 8 8. (1 point) How will the brightness of Bulb D when the switch is open compare to the brightness of Bulb D when the switch is closed? Circuit for Problems 7 and 8 a. Bulb D will be brighter after the switch is closed b. Bulb D will be dimmer after the switch is closed c. The brightness will be the same
Explanation / Answer
7. When the switch is closed, bulbs D and E are connected in parallel across the battery. Net resistance of the circuit will decrease due to parallel connection, and the circuit will draw more current from the battery. But the current through each bulb will be the same, as the potential across each bulb is same. As current through each bulb remains constant, both bulbs will glow with same brightness.
8. The brightness will be the same because the current drawn by Bulb D, when the switch is open, is equal to the current drawn by Bulb D when the switch is closed. It is just that the battery will drain faster, when another bulb is connected in parallel due to decrement in effective resistance.