With reference to street-lighting, how do sodium lamps differ from LED lamps? 1. Sodium lamps produce light…
With reference to street-lighting, how do sodium lamps differ from LED lamps? 1. Sodium lamps produce light in 360 degrees but it is not so in the case of LED lamps. 2. As street-lights, sodium lamps have longer life span than LED lamps. 3. The spectrum of visible light from sodium lamps is almost monochromatic while LED lamps offer significant colour advantages in street-lighting. Select the correct answer using the code given below.
3 only
2 only
1 and 3 only
1, 2 and 3
Solution
Sodium lamps emit light in 360 degrees, while LEDs are directional (Statement 1 correct). LEDs have much longer lifespan than sodium lamps (Statement 2 incorrect). Sodium lamp light is nearly monochromatic (yellow), while LEDs offer better colour rendering (Statement 3 correct).