9. If one bulb of Christmas lights, connected in series is burned out, what will
happen to the other light bulbs?
A. All other bulbs will no longer work.
B. All other bulbs will continue to light
C. The brightness of the bulbs will increase.
D. The brightness of the bulbs will decrease.
10. Three light bulbs with resistances 2000 , 1600 , and 800 are connected in
series respectively. Which one has the highest brightness when the circuit is
plugged to a 220 V voltage source?
A. 800 2
B. 1600 2
C. 2000 2
D. none of the above