The circuit below contains three 100-W light bulbs.The emf $\varepsilon$= 110 V.Which light bulb(s) is(are) brightest?
A)A
B)B
C)C
D)B and C
E)All three are equally bright.

Question

The circuit below contains three 100-W light bulbs.The emf $\varepsilon$= 110 V.Which light bulb(s) is(are) brightest? 
A)A 
B)B 
C)C 
D)B and C 
E)All three are equally bright.

Quizplus · Accepted Answer

Since all three light bulbs are in parallel, they each have the same voltage drop of 110 V. Therefore, the brightness of each bulb is determined only by its power, with a higher power indicating a brighter bulb. Because all three bulbs have the same power of 100 W, they will all have the same brightness. Therefore, the answer is (E) all three are equally bright.

The Circuit Below Contains Three 100-W Light Bulbs ε\varepsilonε = 110 VWhich Light Bulb(s) Is(are) Brightest? A)A B)B C)C D)B

The Circuit Below Contains Three 100-W Light Bulbs $\varepsilon$ = 110 VWhich Light Bulb(s) Is(are) Brightest?
A)A
B)B
C)C
D)B