UPSC CSE Prelims 2021 Q72 — Science & Technology PYQ with Answer

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.

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