1000+ Illumination Multiple Choice Questions and Answers Pdf - 2

Question: 6

In fluorescent tubes ballast resistance is connected in series with the choke

(A) to reduce radio interference

(B) when supply frequency is low

(C) when tube operates on D.C. supply

(D) to reduce stroboscopic effects

Question: 7

The level of illumination on a surface least depends on

(A) type of reflector used

(B) distance of the source

(C) candle power of the source

(D) ambient temperature

Question: 8

A mercury vapour lamp gives _____ light.

(A) greenish blue

(B) yellow

(C) pink

(D) white

Question: 9

Most affected parameter of a filament lamp due to voltage change is

(A) light output

(B) luminous efficiency

(C) life

(D) wattage

Question: 10

Colour of light depends upon

(A) speed of light

(B) frequency

(C) wavelength

(D) both b and c