Illumination objective questions with explanations

Illumination objective questions with explanations

Q no 1. Which of the following statements is correct ?

A ) light is a form of heat energy

B ) light is a form of electrical energy

C ) light consist of shooting particles

D ) light consist of electromagnetic waves

Explanations

                  Answer D ) light consist of electromagnetic waves

Q no 2 . Filament lamps operate normally at a power factor of

A ) 0.5 lagging

B ) 0.8 lagging

C ) unity

D ) 0.8 leading

Explanations

                  Answer C ) unity

Q no 3 . Fine diameter tungsten wires are made by

A ) turning

B ) swaging

C ) compressing

D )wire drawing

Explanations

                  Answer D )wire drawing

Q no 4 . What percentage of the input energy is radiated by filament lamps ?

A ) 2 to 5 %

B ) 10 to 15 %

C ) 25 to 30 %

D ) 40 to 50 %

Explanations

                  Answer C ) 25 to 30 %

Q no 5 .  Which of the following lamps is the cheapest for the same wattage ?

A ) fluorescent tube

B ) mercury vapour lamp

C )GLS lamp

D ) sodium vapour lamp

Explanations

                  Answer C )GLS lamp