What are the laws of illumination?

What are the laws of illumination?
by

1 Answer

Answer :

a. Illumination ‘E’ is directly proportional to the luminous intensity ‘I’ of the source. ie E ∝ I.

b. Inverse square law: The illumination of the surface is inversely proportional to the square of the distance of the surface from the source. ie E ∝ 1/d2 .

c. Illumination ‘E’ is directly proportional to the cosine of angle made by the normal to the illumination surface and the direction of the incident light and is known as lam pod’s cosine angle.
by

Related questions

In a three-phase electrical system, three ground detecting lamps are provided. One lamp goes dark and the others increase in brightness. When the test button is pushed, all lamps have equal illumination. You should conclude that ____________. A. there is a ground on the line with the dark lamp B. the dark lamp must be replaced C. there are grounds on the lines with the bright lamps D. this is a normal condition

Description : In a three-phase electrical system, three ground detecting lamps are provided. One lamp goes dark and the others increase in brightness. When the test button is pushed, all lamps have equal illumination. You ... C. there are grounds on the lines with the bright lamps D. this is a normal condition

Last Answer : Answer: A

An overload in which of the listed motors will result in the illumination of an indicating light at the propulsion control station alarm panel? A. Fuel pump motor B. Steering motor C. Condensate pump motor D. Forced draft blower motor

Description : An overload in which of the listed motors will result in the illumination of an indicating light at the propulsion control station alarm panel? A. Fuel pump motor B. Steering motor C. Condensate pump motor D. Forced draft blower motor

Last Answer : Answer: B

A burned-out LED should be indicated by _____________. A. excessive output B. a slight glow in the crystal C. excessive illumination D. no illumination

Description : A burned-out LED should be indicated by _____________. A. excessive output B. a slight glow in the crystal C. excessive illumination D. no illumination

Last Answer : Answer: D

What are the properties of good illumination?

Description : What are the properties of good illumination?

Last Answer : a. It should have sufficient light. b. It should not strike the eyes. c. It should not produce glares. d. Light should be uniform. e. It should be of harmonious. f. It should be of correct type as needed. g. It should have suitable shade and reflector. h. Economically productive.

What are the factors to be considered for correct illumination?

Description : What are the factors to be considered for correct illumination?

Last Answer : a. Nature of work. b. Determine the foot-candle illumination required after studying the nature of work. Example for precision work - 100 foot candle, for fine engraving - 50 foot candle, for ... . c. Design of apartment using for the proper projection of illumination for better work or purpose.

What is illumination?

Description : What is illumination?

Last Answer : The quantity of a light emitted by a lighting source is known as illumination. Heating effect of electric current is used in producing illumination. When a solid or vapour is heated it begins to radiate ... uniform source of candle power on the inner surface of a sphere of radius one (1) meter.

What is the unit of illumination ?

Description : What is the unit of illumination ?

Last Answer : : The amount of light radius found per unit area of a place is called illumination of that place. So the unit of illumination is lumen / sqft or lumen / sqm. When one lumen of light falls on an area of one square foot, it is called one lumen / square foot or 1 foot candle illumination.

How many sources of illumination ?

Description : How many sources of illumination ?

Last Answer : There are 3 sources of illumination.

A frosted bulb which may be taken as an isotropic source, gives as illumination of `8lm//m^(2)` at a distance of 5m. Calculate (i) its luminous intens

Description : A frosted bulb which may be taken as an isotropic source, gives as illumination of `8lm//m^(2)` at a distance of 5m. Calculate (i) its luminous intens

Last Answer : A frosted bulb which may be taken as an isotropic source, gives as illumination of `8lm//m^(2)` ... and (ii) the total luminous flux from the blub.

An electric bulb illuminates a plane surface. The intensity of illumination on the surface at a point 2m away from the bulb is `5 xx 10^(-4)` phot. Th

Description : An electric bulb illuminates a plane surface. The intensity of illumination on the surface at a point 2m away from the bulb is `5 xx 10^(-4)` phot. Th

Last Answer : An electric bulb illuminates a plane surface. The intensity of illumination on the surface at a point 2m away from the ... ? (1 phot `= 1m//cm^(2))`.

At what distance form a light source of 64 cd, will the intensity of illumination because 4 flux ?

Description : At what distance form a light source of 64 cd, will the intensity of illumination because 4 flux ?

Last Answer : At what distance form a light source of 64 cd, will the intensity of illumination because 4 flux ?

Calculate the intensity of illumination at a distance of 0.5m from a source of light of power 200 candela assuming normal incidence.

Description : Calculate the intensity of illumination at a distance of 0.5m from a source of light of power 200 candela assuming normal incidence.

Last Answer : Calculate the intensity of illumination at a distance of 0.5m from a source of light of power 200 candela assuming normal incidence.

When elaborating a persuasive essay you should . utilize statistics to prove your point consider a variety of points for illumination limit your elaboration to provable facts avoid using technical lan?

Description : When elaborating a persuasive essay you should . utilize statistics to prove your point consider a variety of points for illumination limit your elaboration to provable facts avoid using technical lan?

Last Answer : Need answer

Does this Seiko men's diving watch have a source of illumination?

Description : Does this Seiko men's diving watch have a source of illumination?

Last Answer : Seiko men's diving watch doesn't have any source of illumination

Lambert's law is related to – (1) Reflection (2) Refraction (3) Interference (4) Illumination

Description : Lambert's law is related to – (1) Reflection (2) Refraction (3) Interference (4) Illumination

Last Answer : (4) Illumination Explanation: In optics, Lambert's cosine law says that the radiant intensity or luminous intensity observed from an ideal diffusely reflecting surface or ideal diffuse radiator is directly proportional ... . The law is also known as the cosine emission law or Lambert's emission law.

Lamberts law is related to – (1) Reflection (2) Refraction (3) Interference (4) Illumination

Description : Lamberts law is related to – (1) Reflection (2) Refraction (3) Interference (4) Illumination

Last Answer : (4) Illumination Explanation: Lambert's Law says that the intensity of emitted light from a surface is directly proportional to the cosine of the angle between the line of view and the normal ... , and exhibits Lambertian reflectance. Such a surface has the same radiance when viewed from any angle.

Lux is the SI unit of - (1) intensity of illumination (2) luminous efficiency (3) luminous flux (4) luminous intensity

Description : Lux is the SI unit of - (1) intensity of illumination (2) luminous efficiency (3) luminous flux (4) luminous intensity

Last Answer : (1) intensity of illumination Explanation: The SI unit of intensity of illumination (illuminance) is the lux. An illuminance of 1.0 lux is produced by 1.0 lumen of light shining on an area of 1.0 m2.

What illumination factor is normally considered in computing parabolic antenna gain in microwave communications? A. 0.54 B. 0.65 C. 0.75 D. 0.85

Description : What illumination factor is normally considered in computing parabolic antenna gain in microwave communications? A. 0.54 B. 0.65 C. 0.75 D. 0.85

Last Answer : A. 0.54

What is the difference between a sodium vapour lamp, Which gives out a yellowish colour illumination, and a mercury vapour lamp that gives out a white colour illumination?

Description : What is the difference between a sodium vapour lamp, Which gives out a yellowish colour illumination, and a mercury vapour lamp that gives out a white colour illumination?

Last Answer : Answer I: The light in Sodium Vapour lamp is from an atomic emission process whereas in Mercury Vapour Lamp it is, finally, from fluorescence emission. The mechanism of light emission in a sodium ... from a fluorescent lamp is moderate (60 lumens/watt) while the color-rendering index is high.

The visual acuity is affected by: a. pupil size b. illumination of the target c. red-green colour blindness d. contrast

Description : The visual acuity is affected by: a. pupil size b. illumination of the target c. red-green colour blindness d. contrast

Last Answer : contrast

Pick out the wrong statement. (A) Strongly caking coal should not be used in the Lurgi gasifier (B) Acetylene gas cannot be used for illumination purpose (C) Water gas is called blue gas because of the color of the flame, when it is burnt (D) Gaseous fuels require less percentage of excess air for combustion as compared to liquid fuels

Description : Pick out the wrong statement. (A) Strongly caking coal should not be used in the Lurgi gasifier (B) Acetylene gas cannot be used for illumination purpose (C) Water gas is called blue gas ... is burnt (D) Gaseous fuels require less percentage of excess air for combustion as compared to liquid fuels

Last Answer : (B) Acetylene gas cannot be used for illumination purpose

Earth observations from a satellite platform provide: (A) Synoptic view of a large area (B) Constant solar zenith angles and similar illumination conditions (C) Repetitive observations of the same area with intervals of a few minutes to a few weeks (D) All of these

Description : Earth observations from a satellite platform provide: (A) Synoptic view of a large area (B) Constant solar zenith angles and similar illumination conditions (C) Repetitive observations of the same area with intervals of a few minutes to a few weeks (D) All of these

Last Answer : Answer: Option D

As per IRC recommendations, the average level of illumination on important roads carrying fast traffic is (A) 10 Lux (B) 15 Lux (C) 20 Lux (D) 30 Lux

Description : As per IRC recommendations, the average level of illumination on important roads carrying fast traffic is (A) 10 Lux (B) 15 Lux (C) 20 Lux (D) 30 Lux

Last Answer : Answer: Option D

Lux meter is used to measure…… a) Illumination level b) Sound intensity and illumination level c) Harmonics d) Speed

Description : Lux meter is used to measure…… a) Illumination level b) Sound intensity and illumination level c) Harmonics d) Speed

Last Answer : Illumination level

Lux meter is used to measure…… c) Illumination level c) Harmonics d) Sound intensity and illumination level d) Speed

Description : Lux meter is used to measure…… c) Illumination level c) Harmonics d) Sound intensity and illumination level d) Speed

Last Answer :  Illumination level

116. Lux meter is used to measure…… a) Illumination level c) Harmonics b) Sound intensity and illumination level d) Speed

Description : Lux meter is used to measure…… a) Illumination level c) Harmonics b) Sound intensity and illumination level d) Speed

Last Answer : Illumination level

______ meter is used to measure Illumination level a. Pyrometer b. Wattmeter c. Lux meter d. All

Description : ______ meter is used to measure Illumination level a. Pyrometer b. Wattmeter c. Lux meter d. All

Last Answer : Ans:- c. Lux meter

The minimum optical power a light detector can receive and still produce a usable electrical output signal. ∙ A. light responsivity ∙ B. light sensitivity ∙ C. light collectivity ∙ D. illumination

Description : The minimum optical power a light detector can receive and still produce a usable electrical output signal. ∙ A. light responsivity ∙ B. light sensitivity ∙ C. light collectivity ∙ D. illumination

Last Answer : B. light sensitivity

What is the recommended minimum range of illumination required by BS EN 970 for inspection of a welded surface? a) 90 to 125 lux b) 150 to 250 lux c) 350 to 500 lux d) 35 to 50 lux

Description : What is the recommended minimum range of illumination required by BS EN 970 for inspection of a welded surface? a) 90 to 125 lux b) 150 to 250 lux c) 350 to 500 lux d) 35 to 50 lux

Last Answer : c) 350 to 500 lux

In interference experiment, by keeping all other parameters constant, if you see the thin film interference from different angles, you will observe (a)Uniform illumination of screen (b) Uniform darkness on the screen (c) Equally spaced dark and white bands (d) Few colored bands and then general illumination

Description : In interference experiment, by keeping all other parameters constant, if you see the thin film interference from different angles, you will observe (a)Uniform illumination of screen (b) Uniform ... c) Equally spaced dark and white bands (d) Few colored bands and then general illumination

Last Answer : (d) Few colored bands and then general illumination

In interference experiment, monochromatic light is replaced by white light, we will see (a) Uniform illumination of screen (b) Uniform darkness on the screen (c) Equally spaced dark and white bands (d) Few colored bands and then general illumination

Description : In interference experiment, monochromatic light is replaced by white light, we will see (a) Uniform illumination of screen (b) Uniform darkness on the screen (c) Equally spaced dark and white bands (d) Few colored bands and then general illumination

Last Answer : (d) Few colored bands and then general illumination

Please indicate the illumination levels provided at following locations?

Description : Please indicate the illumination levels provided at following locations?

Last Answer : Ans. a. ASM Room: 100 lux and above b. Booking Window:400 lux and above c. Officers Chamber: 120 lux and above. d. Operation theatre in Hospital.

In which stage of the conflict process does conflict become visible? (a) Illumination ; (b) Intentions ; (c) Behaviour ; (d) Cognition

Description : In which stage of the conflict process does conflict become visible? (a) Illumination ; (b) Intentions ; (c) Behaviour ; (d) Cognition 

Last Answer : (c) Behaviour ;

A far-sighted person, without optical correction, is typically able to see nearby objects more clearly in bright light. The reason for this phenomena is: w) bright light provides better illumination. x) the pupil of the eye narrows which increases the depth of focus. y) the pupil of the eye widens which increases the depth of focus. z) the bright light causes squinting which flattens the eyeball which tends to correct the far-sighted condition.

Description : A far-sighted person, without optical correction, is typically able to see nearby objects more clearly in bright light. The reason for this phenomena is: w) bright light provides better ... bright light causes squinting which flattens the eyeball which tends to correct the far-sighted condition.

Last Answer : ANSWER: X -- THE PUPIL OF THE EYE NARROWS WHICH INCREASES THE DEPTH OF FOCUS

Lamberts law is related to (1) Reflection (2) Refraction (3) Interference (4) Illumination

Description : Lamberts law is related to (1) Reflection (2) Refraction (3) Interference (4) Illumination

Last Answer : Illumination

State the requirements of illumination scheme of shipyard.

Description : State the requirements of illumination scheme of shipyard.

Last Answer : Requirements of illumination scheme of shipyard:  1) The shipyard lighting always depends upon the surrounding conditions. e.g. wind pressure, rain fall, location of shipyard from the sea-share etc. ... solar grass lamps, LED-Solar energy lawn lamps, various focus lamps, metal halide lamps etc.

State design considerations for illumination scheme of commercial complex.

Description : State design considerations for illumination scheme of commercial complex.

Last Answer : Design considerations for illumination scheme of commercial complex: * Tasks to be performed in the space * Desired light levels based on the tasks performed in the space * Room size ... conditions * Cleanliness of the area during operation * Maintenance schedule * Availability of daylight

Use of polar curves in illumination Engg

Description : Use of polar curves in illumination Engg

Last Answer : The polar curves are required to determine the mean horizontal candle power (MHCP) and mean hemispherical candle power (MHSCP).The polar curves are due to limitations of unsymmetrical design shape of ... lighting scheme. 2. To know the intensity of light emitted by the source in different direction

Define each of following terms of illumination — lux, lumen, luminous flux, illumination.

Description : Define each of following terms of illumination — lux, lumen, luminous flux, illumination.

Last Answer : i) Lux :- It is unit of illumination and it is defined as luminous flux falling per unit area  ii) Lumen: It is defined as the luminous flux emitted by a source of one candle power per unit ... the given surface on the working plane. The unit of illumination is lumens/m2 OR lumens/m2 = 1 Lux

A 500 W bulb fitted with a reflector illuminates an area of 2 m x 2 m with an average illumination of 500 lux.

Description : A 500 W bulb fitted with a reflector illuminates an area of 2 m x 2 m with an average illumination of 500 lux. The efficiency of the reflector is 50%. The efficiency of the bulb in lumens/watt is : 

Last Answer : A 500 W bulb fitted with a reflector illuminates an area of 2 m x 2 m with an average illumination of 500 lux. The efficiency of the reflector is 50%. The efficiency of the bulb in lumens/watt is : 8

The unit of illumination is: -

Description : The unit of illumination is: -  a) amperes b) lumens c) lux d) candela

Last Answer : The unit of illumination is: - lux

If the total source voltage of the three-wire distribution system shown in the illustration is 240 volts, what is the voltage across load L5? [ NOTE: Kirchhoff's voltage and current laws apply ] EL-0075 A. 110.4 volts B. 112.2 volts C. 113.0 volts D. 114.8 volts

Description : If the total source voltage of the three-wire distribution system shown in the illustration is 240 volts, what is the voltage across load L5? [ NOTE: Kirchhoff's voltage and current laws apply ] EL-0075 A. 110.4 volts B. 112.2 volts C. 113.0 volts D. 114.8 volts

Last Answer : Answer: D

If the total source voltage of the three-wire distribution system shown in the illustration is 240 volts, what is the voltage across load L1? [NOTE: Kirchhoff's voltage and current laws apply.] EL-0075 A. 110.4 volts B. 112.2 volts C. 113.3 volts D. 114.8 volts

Description : If the total source voltage of the three-wire distribution system shown in the illustration is 240 volts, what is the voltage across load L1? [NOTE: Kirchhoff's voltage and current laws apply.] EL-0075 A. 110.4 volts B. 112.2 volts C. 113.3 volts D. 114.8 volts

Last Answer : Answer: D

If the total source voltage of the three-wire distribution system shown in the illustration is 240 volts, what is the voltage across load L2? [NOTE: Kirchhoff's voltage and current laws apply.] EL-0075 A. 110.4 volts B. 112.2 volts C. 113.0 volts D. 114.8 volts

Description : If the total source voltage of the three-wire distribution system shown in the illustration is 240 volts, what is the voltage across load L2? [NOTE: Kirchhoff's voltage and current laws apply.] EL-0075 A. 110.4 volts B. 112.2 volts C. 113.0 volts D. 114.8 volts

Last Answer : Answer: C

If the total source voltage of the three-wire distribution system shown in the illustration is 240 volts, what is the voltage across load L3? [NOTE: Kirchhoff's voltage and current laws apply.] EL-0075 A. 110.4 volts B. 112.2 volts C. 113.0 volts D. 114.8 volts

Description : If the total source voltage of the three-wire distribution system shown in the illustration is 240 volts, what is the voltage across load L3? [NOTE: Kirchhoff's voltage and current laws apply.] EL-0075 A. 110.4 volts B. 112.2 volts C. 113.0 volts D. 114.8 volts

Last Answer : Answer: B

Explain Kirchhoff’s laws.

Description : Explain Kirchhoff’s laws.

Last Answer : Kirchhoff's laws are used in complex network circuits to determine the equivalent total resistance and the current flowing in various conductors of that circuit. Mainly there are two laws. a. Point law ... . In this the important factor is to determine the emf sign to calculate the total emf.

State the faraday’s laws of electro magnetic induction.

Description : State the faraday’s laws of electro magnetic induction.

Last Answer : In 1831 Faraday discovered the production of electric current in electric conductor by converting magnetism. Faraday has mentioned two laws known as faraday's laws of electro magnetic induction. First ... conductor is directly proportional to the rate of change of flux linked with that conductor. 

State the laws of magnetism.

Description : State the laws of magnetism. 

Last Answer : a. Magnet imparts its magnetic properties to other metals. b. When a magnet is suspended freely horizontally, it stands at geographical north and south. c. Every magnet has a north and its associated ... to the square of the distance between them. This is some times known as inverse square law.

What are the Faradays laws of electrolysis?

Description : What are the Faradays laws of electrolysis?

Last Answer : First law The mass ions liberated at an electrode are directly proportional to the quantity of electricity (coulomb Q) which has passed through the electrolyte. That is M∝Q or M∝I ... several electrolyte the masses of the ions liberated are proportional to their respective chemical equivalent.