The sodium lamp has some advantage over the mercury lamp such as
(i) for a given input of electricity, the sodium lamp gives off greater light intensity than does the mercury lamp.
(ii) yellow light has a longer wavelength than bluish-green light.
(iii) human eye exhibits its greatest reponse for yellow color.

Options

A. `(i),(iii)`
B. `(ii),(iii)`
C. `(i),(ii),(iii)`
D. `(i),(ii)`

Answer

C

Explanation

Due to longer wavelength, yellow light is not scatered as much by small particles is the air-fog, for example, and penetrates farther than white light. Moreover, you many have noticed that some autmobile fog lights have yellowtinted glass covers.