During a brown-out, the electric power company drops the voltage of the power line and the incandescent
light bulbs in your house become dimmer. When this happens, the filaments in the bulbs operate at a
lower than normal temperature, so
a. their color is somewhat bluer than normal.
b. they emit ultraviolet light.
c. their color is the same as normal, but they are less bright.
d. their color is somewhat redder than normal.
e. they burn out more quickly.
During a brown-out, when the electric power company drops the voltage of the power line, the incandescent light bulbs in your house become dimmer. This happens because the lower voltage leads to a decrease in the amount of electrical current flowing through the filament of the bulb.
Now, let's analyze the options given:
a. Their color is somewhat bluer than normal.
Incorrect. The color of incandescent bulbs is determined by the temperature of the filament, and when the voltage is lowered, the filament operates at a lower temperature. A lower temperature typically results in a redder color, rather than a bluer color.
b. They emit ultraviolet light.
Incorrect. Incandescent bulbs primarily emit visible light, with a small amount of infrared radiation. Ultraviolet light is not typically emitted by incandescent bulbs.
c. Their color is the same as normal, but they are less bright.
Correct. When the voltage is lowered, the filament operates at a lower temperature, resulting in a dimmer light output. However, the color of the light remains relatively unchanged.
d. Their color is somewhat redder than normal.
Correct. As mentioned earlier, when the filament operates at a lower temperature, the color of the light emitted tends to shift towards the red end of the spectrum.
e. They burn out more quickly.
Incorrect. Lowering the voltage may actually extend the lifespan of incandescent bulbs since the lower temperature puts less stress on the filament. However, it is worth noting that incandescent bulbs, in general, have a shorter lifespan compared to other types of bulbs.
Therefore, the correct answer is: c. Their color is the same as normal, but they are less bright, and d. Their color is somewhat redder than normal.