Lamps are usually selected according to their_____
a. voltage rating
b. wattage rating
c. size
d. shape
The correct answer and explanation is:
The correct answer is b. wattage rating.
Lamps are typically selected based on their wattage rating, which indicates the amount of electrical power they consume and, indirectly, the amount of light they produce. Wattage helps determine how much energy a lamp will use over time. The higher the wattage, the more energy it uses, and in most cases, the more light it produces. For example, a 100-watt incandescent bulb will produce more light than a 40-watt bulb, but it will also consume more energy.
When selecting a lamp, the wattage rating ensures that the correct amount of light is provided for a given space or application. The wattage rating is also crucial for matching the lamp to the electrical system in which it will be used. Using a lamp with too high or too low a wattage rating for a fixture can result in safety issues, such as overheating or insufficient lighting.
Voltage rating is also important, but it’s typically standardized for specific regions (e.g., 120V in the U.S.), so it is less of a determining factor when selecting a lamp. Similarly, the size and shape of the lamp are relevant for fitting it into particular fixtures or aesthetic preferences, but they do not directly influence the lamp’s function as much as the wattage rating does.
In modern applications, especially with energy-efficient lighting like LEDs, wattage can be a less direct measure of light output. LEDs, for example, use much less wattage to produce the same amount of light as incandescent bulbs, which is why energy efficiency and lumen output (a measure of light produced) are becoming more common factors in lamp selection.