Question 1

Which of the following instruments is used for the comparison of candle powers of different sources?
A)radiometer
B)bunsen meter
C)photometer
D)candle meter

Accepted Answer

Photometers are instruments used to measure the intensity of light, making them suitable for comparing the candle powers (a measure of light intensity) of different light sources.

Question 2

The illumination at various points on a horizontal surface illuminated by the same source varies as A)cos3? B)cos ? C)1/r² D)cos2?.

Accepted Answer

A

Question 3

Floodlighting is NOT used for purposes.
A)reading
B)aesthetic
C)advertising
D)industrial.

Accepted Answer

Floodlighting is typically used for aesthetic, advertising, and industrial purposes, but it is not suitable for reading due to its broad and powerful light distribution which can cause glare and discomfort rather than the focused and softer lighting required for reading.

Question 4

Which of the following lamp has minimum initial cost of installation but maximum running cost ?
A)incandescent
B)fluorescent
C)mercury vapour
D)sodium vapour.

Accepted Answer

Incandescent lamps have the lowest initial cost compared to fluorescent, mercury vapor, and sodium vapor lamps. However, they are less energy-efficient, leading to higher running costs over time due to their lower luminous efficacy and shorter lifespan.

Question 5

Candela is the unit of which of the following?
A)wavelength
B)luminous intensity
C)luminous flux
D)frequency

Accepted Answer

Candela is the SI unit of luminous intensity, which measures the power emitted by a light source in a particular direction, weighted by the luminous efficacy perceived by the human eye.

Question 6

Colour of light depends upon
A)frequency
B)wave length
C)both (a) and (b)
D)speed of light

Accepted Answer

The color of light is determined by its frequency and wavelength. These two properties are directly related; as the frequency of light increases, its wavelength decreases, and vice versa, both influencing the perceived color.

Question 7

Illumination of one lumen per sq. metre is called
A)lumen metre
B)lux
C)foot candle
D)candela

Accepted Answer

Lux is the SI unit of illuminance, measuring luminous flux per unit area. It is equivalent to one lumen per square meter.

Question 8

A solid angle is expressed in terms of
A)radians/metre
B)radians
C)steradians
D)degrees

Accepted Answer

A solid angle is expressed in terms of steradians, which is the SI unit for measuring the size of a three-dimensional angle.

Question 9

The unit of luminous flux is . A)watt/m² B)lumen C)lumen/m² D)watt

Accepted Answer

Luminous flux is measured in lumens, which quantifies the amount of visible light emitted by a source.

Question 10

Filament lamps operate normally at a power factor of
A)0.5 lagging
B)0.8 lagging
C)unity
D)0.8 leading

Accepted Answer

Filament lamps are purely resistive loads, meaning they do not have any inductive or capacitive components that would cause a phase shift between voltage and current. Therefore, their power factor is unity (1), indicating that all the power is being used effectively.

Question 11

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

Accepted Answer

GLS (General Lighting Service) lamps, commonly known as incandescent bulbs, are typically the cheapest option for the same wattage compared to more energy-efficient or specialized lighting options like fluorescent tubes, mercury vapor lamps, or sodium vapor lamps. This is due to their simpler design and widespread manufacturing.

Question 12

On which of the following factors dies the depreciation or maintenance factor depend?
A)lamp cleaning schedule
B)ageing of the lamp
C)type of work carried out at the premises
D)all of the above factors

Accepted Answer

The depreciation or maintenance factor of lighting systems depends on various factors including the lamp cleaning schedule, the ageing of the lamp, and the type of work carried out at the premises. These factors collectively influence how quickly a lighting system may degrade and require maintenance or replacement.

Question 13

For the same lumen output, the running cost of the fluorescent lamp is
A)equal to that of filament lamp
B)less than that of filament lamp
C)more than that of filament lamp
D)any of the above

Accepted Answer

Fluorescent lamps are more energy-efficient than filament lamps (incandescent bulbs). For the same lumen output, they consume less power, leading to lower running costs.

Question 14

The flicker effect of fluorescent lamps is more pronounced at
A)lower frequencies
B)higher frequencies
C)lower voltages
D)higher voltages

Accepted Answer

The flicker effect in fluorescent lamps is more pronounced at lower frequencies because the lamp has a chance to start dimming between cycles, creating a noticeable flicker. At higher frequencies, this effect is minimized because the cycles are closer together, giving less time for the light output to decrease between them.

Question 15

...... is a cold cathode lamp.
A)fluorescent lamp
B)neon lamp
C)mercury vapour lamp
D)sodium vapour lamp

Accepted Answer

Neon lamps are a type of cold cathode lamp, which means they do not rely on heating a filament to produce light. Instead, they operate by ionizing gas in a sealed glass tube, which produces a glow when electricity is applied.

Question 16

For normal reading the illumination level required is around A)20-40 lumens/m² B)60-100 lumens/m² C)200-300 lumens/m² D)400-500 lumens/m²

Accepted Answer

The answer of For normal reading the illumination level required...

Question 17

Which gas can be filled in GLS lamps?
A)oxygen
B)carbon dioxide
C)xenon
D)any inert gas

Accepted Answer

GLS (General Lighting Service) lamps can be filled with any inert gas, such as argon, neon, or krypton, to prevent the filament from oxidizing and burning out quickly. Inert gases do not react with the filament even at high temperatures, thereby prolonging the life of the lamp.

Question 18

Which of the following is not the type of refrigerant?
A)organic refrigerants
B)inorganic refrigerants
C)azeotrope refrigerants
D)halo-helium refrigerants

Accepted Answer

Halo-helium refrigerants do not exist as a recognized category of refrigerants. The recognized types include organic, inorganic, and azeotrope refrigerants.

Question 19

The refrigerants which are first cooled by-----------------refrigerants and then used for cooling purposes are known as---------------refrigerants.
A)secondary, primary
B)primary, secondary
C)tertiary, primary
D)secondary, tertiary

Accepted Answer

Primary refrigerants are those that absorb heat directly from the substance or space being cooled, while secondary refrigerants are first cooled by primary refrigerants and then used for cooling purposes.

Question 20

Which one of the following inorganic refrigerants is often used? A)nh3 B)CO₂ C)H₂o D)sO₂

Accepted Answer

NH3, or ammonia, is a widely used inorganic refrigerant due to its excellent thermodynamic properties and efficiency in large industrial refrigeration systems.

Quiz 1: Lighting and Refrigeration Systems

Which of the following instruments is used for the comparison of candle powers of different sources?

The illumination at various points on a horizontal surface illuminated by the same source varies as

Floodlighting is NOT used for purposes.

Which of the following lamp has minimum initial cost of installation but maximum running cost ?

Candela is the unit of which of the following?

Colour of light depends upon

Illumination of one lumen per sq. metre is called

A solid angle is expressed in terms of

The unit of luminous flux is .

Filament lamps operate normally at a power factor of

Which of the following lamps is the cheapest for the same wattage?

On which of the following factors dies the depreciation or maintenance factor depend?

For the same lumen output, the running cost of the fluorescent lamp is

The flicker effect of fluorescent lamps is more pronounced at

...... is a cold cathode lamp.

For normal reading the illumination level required is around

Which gas can be filled in GLS lamps?

Which of the following is not the type of refrigerant?

The refrigerants which are first cooled by-----------------refrigerants and then used for cooling purposes are known as---------------refrigerants.

Which one of the following inorganic refrigerants is often used?