ILLUMINATION QUIZ

Candela is the unit of which?

Luminous flux.

Luminous intensity.

Frequency.

Wavelength.

TRUE ANSWER : ?
YOUR ANSWER : ?

A 1000 W bulb fitted with a reflector illuminates an area of 3 m x 3 m with an average illumination of 450 lux. If the bulb has and efficiency of 9 lumens / watt the efficiency of the reflector is

20 %.

30 %.

70 %.

45 %.

TRUE ANSWER : ?
YOUR ANSWER : ?

Luminous efficiency of a fluorescence lamp is

40 lumens / watt.

30 lumens / watt.

70 lumens / watt.

60 lumens / watt.

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YOUR ANSWER : ?

The illumination of the surface varies directly with cosine of the angle between normal to surface and direction of the inclined light is given by

None of these

both A and B.

Lambert’s cosine law.

law of square inverse.

TRUE ANSWER : ?
YOUR ANSWER : ?

Solid angle is expressed in terms of

degree.

radians / meter.

radians.

steredians.

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YOUR ANSWER : ?

What is the ratio of illuminance at a point 5m just below a lamp emitting 100 candelas and at a point 5m away from the first point on the same horizontal plane?

1:2

2√2 : 1

2:1

1: 2√2

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YOUR ANSWER : ?

Which cells in the eye are responsible for scotopic vision?

None of these

Cone cells

Rod cells

Both ‘a’ and ‘b’

TRUE ANSWER : ?
YOUR ANSWER : ?

Total flux or lumens required in any lighting scheme depends inversely on

utilization factor.

reflection factor.

None of these

reduction factor.

TRUE ANSWER : ?
YOUR ANSWER : ?

What is the work of a driver in case of an LED?

To convert DC to AC

To convert AC to DC

None of these

Both ‘a’ and ‘b’

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YOUR ANSWER : ?

Which lamp is best suited for lighting an International sports arena?

Compact Fluorescent

LED

Incandescent

Metal Halide

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YOUR ANSWER : ?

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