What must happen a substance to appear black what must happen to all wavelengths of light?

What must happen a substance to appear black what must happen to all wavelengths of light?
by

1 Answer

Answer :

A substance that appears black (in a lighted room) is absorbingall of the visible light that hits it, leaving no visible light toreflect off of it to your eye. So it's absorbing visible light ofall wavelengths. (You still don't know what's happening to theinfra-red or ultraviolet hitting it. For that, you need to usedifferent detectors.)
by
selected by

Related questions

When the frequency is decreased so that two quarter wavelengths are longer than the "a" (wide) dimension of the waveguide, what will happen?

Description : When the frequency is decreased so that two quarter wavelengths are longer than the "a" (wide) dimension of the waveguide, what will happen?

Last Answer : Energy will no longer pass through the waveguide.

A black body can absorb radiations of (1) lower wavelengths only (2) intermediate wavelengths only (3) higher wavelengths only (4) all wavelengths

Description : A black body can absorb radiations of (1) lower wavelengths only (2) intermediate wavelengths only (3) higher wavelengths only (4) all wavelengths

Last Answer : (4) all wavelengths Explanation: A black body is a theoretical object that absorbs 100% of the radiation that hits it. Therefore it reflects no radiation and appears perfectly black. At a particular ... as it must be able to absorb every wavelength to be sure of absorbing all incoming radiation.

A black body when hot, emits heat radiation of __________ wavelengths. (A) Small (B) Large (C) All (D) One fixed

Description : A black body when hot, emits heat radiation of __________ wavelengths. (A) Small (B) Large (C) All (D) One fixed

Last Answer : (C) All

Maximum amount of thermal radiation is emitted at all wavelengths at any specified temperature by a/an __________ body. (A) Grey (B) Black (C) Opaque

Description : Maximum amount of thermal radiation is emitted at all wavelengths at any specified temperature by a/an __________ body. (A) Grey (B) Black (C) Opaque

Last Answer : (A) Grey

A black body can absorb radiations of ; (1) lower wavelengths only (2) intermediate wavelengths only (3) higher wavelengths only (4) all wavelengths

Description : A black body can absorb radiations of ; (1) lower wavelengths only (2) intermediate wavelengths only (3) higher wavelengths only (4) all wavelengths

Last Answer : all wavelengths

A beam of ultraviolet light of all wavelengths passes through hydrogen gas at room temperature, in the x. dimction. Assume thatall photons emitted due

Description : A beam of ultraviolet light of all wavelengths passes through hydrogen gas at room temperature, in the x. dimction. Assume thatall photons emitted due

Last Answer : A beam of ultraviolet light of all wavelengths passes through hydrogen gas at room temperature, in the ... light D. B will contain some visible light

Which one of the following wavelengths of light is most effective in photosynthesis? (1) Blue (2) Green (3) Orange (4) Yellow

Description : Which one of the following wavelengths of light is most effective in photosynthesis? (1) Blue (2) Green (3) Orange (4) Yellow

Last Answer : (1) Blue Explanation: Photosynthesis, process by which green plants and certain other organisms use the energy of light to convert carbon dioxide and water into the simple sugar glucose. The wavelength ... of the spectrum, which makes up between 1 and 10% of the light needed for photosynthesis.

Is the width of the range of wavelengths emitted by the light source a. Bandwidth b. Chromatic Dispersion c. Spectral width d. Beamwidth

Description : Is the width of the range of wavelengths emitted by the light source a. Bandwidth b. Chromatic Dispersion c. Spectral width d. Beamwidth

Last Answer : c. Spectral width

The band of light wavelengths that are too long to be seen by the human eye a. Amber b. Visible c. Infrared d. Ultraviolet

Description : The band of light wavelengths that are too long to be seen by the human eye a. Amber b. Visible c. Infrared d. Ultraviolet

Last Answer : c. Infrared

Purkinje's shift: a. refers to the transition of retinal sensitivity between photopic and scotopic vision b. refers to the shift in the spectral sensitivity of the human retina toward shorter wavelengths of light c. accounts for blue colour appearing brighter at dusk d. all above

Description : Purkinje's shift: a. refers to the transition of retinal sensitivity between photopic and scotopic vision b. refers to the shift in the spectral sensitivity of the human retina toward shorter wavelengths of light c. accounts for blue colour appearing brighter at dusk d. all above

Last Answer : all above

With regard to light perception: a. the fovea contains only cones b. the cones have a lower threshold to light than rods c. rods respond most to the red-yellow end of light d. rods respond most to wavelengths of about 500nm

Description : With regard to light perception: a. the fovea contains only cones b. the cones have a lower threshold to light than rods c. rods respond most to the red-yellow end of light d. rods respond most to wavelengths of about 500nm

Last Answer : rods respond most to wavelengths of about 500nm

Sodium fluorescein: a. has a higher affinity for plasma protein than indocyanine green. b. does not leak from the choroidal vasculature. c. does not leak from normal retinal vasculature. d. emits light of longer wavelengths than the one it absorbs

Description : Sodium fluorescein: a. has a higher affinity for plasma protein than indocyanine green. b. does not leak from the choroidal vasculature. c. does not leak from normal retinal vasculature. d. emits light of longer wavelengths than the one it absorbs

Last Answer : does not leak from normal retinal vasculature.

What unit is used to measure the different wavelengths of light?

Description : What unit is used to measure the different wavelengths of light?

Last Answer : Angstrom unit.

Dense ____________________ allows many different wavelengths of light to share a cable.

Description : Dense ____________________ allows many different wavelengths of light to share a cable.

Last Answer : WDM

EMD is best described by which statement? ∙ A. 70 percent of the core diameter and 70% of the fiber NA should be filled with light. ∙ B. 70 percent of the fiber diameter and 70% of the cone of acceptance should be filled with light. ∙ C. 70 percent of input light should be measured at the output. ∙ D. 70 percent of the unwanted wavelengths should be attenuated by the fiber.

Description : EMD is best described by which statement? ∙ A. 70 percent of the core diameter and 70% of the fiber NA should be filled with light. ∙ B. 70 percent of the fiber diameter and 70% of the ... be measured at the output. ∙ D. 70 percent of the unwanted wavelengths should be attenuated by the fiber.

Last Answer : 70 percent of the core diameter and 70% of the fiber NA should be filled with light.

Is the width of the range of wavelengths emitted by the light source ∙ a. Bandwidth ∙ b. Chromatic Dispersion ∙ c. Spectral width ∙ d. Beamwidth

Description : Is the width of the range of wavelengths emitted by the light source ∙ a. Bandwidth ∙ b. Chromatic Dispersion ∙ c. Spectral width ∙ d. Beamwidth

Last Answer : c. Spectral width

The band of light wavelengths that are too short to be seen by the human eye ∙ a. Amber ∙ b. Visible ∙ c. Infrared ∙ d. Ultraviolet

Description : The band of light wavelengths that are too short to be seen by the human eye ∙ a. Amber ∙ b. Visible ∙ c. Infrared ∙ d. Ultraviolet

Last Answer : c. Infrared

The band of light wavelengths that are too long to be seen by the human eye ∙ a. Amber ∙ b. Visible ∙ c. Infrared ∙ d. Ultraviolet

Description : The band of light wavelengths that are too long to be seen by the human eye ∙ a. Amber ∙ b. Visible ∙ c. Infrared ∙ d. Ultraviolet

Last Answer : c. Infrared

EMDis best describe bywhich statement? a. 70percentofthe corediameter and70%ofthefiberNAshouldbe filled with light b.70 percent of the fiber diameter and 70% of the cone of acceptance should be filled with light c.70 percent of input light should be measured at the output d.70 percent of the unwanted wavelengths should be attenuated by the fiber

Description : EMDis best describe bywhich statement? a. 70percentofthe corediameter and70%ofthefiberNAshouldbe filled with light b.70 percent of the fiber diameter and 70% of the cone of acceptance should be filled with ... the output d.70 percent of the unwanted wavelengths should be attenuated by the fiber

Last Answer : a. 70percentofthe corediameter and70%ofthefiberNAshouldbe filled with light

Given light of wavelength λa = 600nm and light of λb = 550nm, which has a higher energy per photon? (a) Ea > Eb (b) Ea = Eb (c) Neither has energy because light at these wavelengths carries no energy (d) Eb > Ea

Description : Given light of wavelength λa = 600nm and light of λb = 550nm, which has a higher energy per photon? (a) Ea > Eb (b) Ea = Eb (c) Neither has energy because light at these wavelengths carries no energy (d) Eb > Ea

Last Answer : (d) Eb > Ea

What is true for intensity of scattered light according to Rayleigh’s law? A. The intensity for scattering for light of largest wavelength more B. The light of smallest wavelength will be scattered more C. All the wavelengths are scattered equally D. Intensity of light is not affected by scattering

Description : What is true for intensity of scattered light according to Rayleigh's law? A. The intensity for scattering for light of largest wavelength more B. The light of smallest wavelength will be scattered ... C. All the wavelengths are scattered equally D. Intensity of light is not affected by scattering

Last Answer : B. The light of smallest wavelength will be scattered more

Which one of the following wavelengths of light is most effective in photosynthesis ? (1) Blue (2) Green (3) Orange (4) Yellow

Description : Which one of the following wavelengths of light is most effective in photosynthesis ? (1) Blue (2) Green (3) Orange (4) Yellow

Last Answer : Blue

Why does a green apple appear black under a red light?

Description : Why does a green apple appear black under a red light?

Last Answer : What is the answer ?

A ray of white light strikes the surface of an object. If all the colours are reflected, the surface would appear (1) Black (2) White (3) Grey (4) Opaque

Description : A ray of white light strikes the surface of an object. If all the colours are reflected, the surface would appear (1) Black (2) White (3) Grey (4) Opaque

Last Answer : (2) White Explanation: Objects do not have any colour of their own. When light hits a surface, some of it is absorbed and some of it is reflected. The light that is reflected is ... appear white when they reflect all the wavelengths; they appear black when they absorb all visible wavelengths.

When light waves encounter any substance, what four things can happen?

Description : When light waves encounter any substance, what four things can happen?

Last Answer : Light waves are either transmitted, refracted, reflected, or absorbed.

How do I calculate these problems wavelengths in nm?

Description : How do I calculate these problems wavelengths in nm?

Last Answer : 1) an 83.0 kg athlete running a "4-minute mile" (i.e. 4.00 min/mile) 2) Earth (mass = 6.00 × 1027 g) moving through space at 2.90 × 104 m/s

A dye absorbs a photon of wavelength `lambda` and re`-` emits the same energy into two phorons of wavelengths `lambda_(1)` and `lambda_(2)` respective

Description : A dye absorbs a photon of wavelength `lambda` and re`-` emits the same energy into two phorons of wavelengths `lambda_(1)` and `lambda_(2)` respective

Last Answer : A dye absorbs a photon of wavelength `lambda` and re`-` emits the same energy into two phorons of wavelengths ` ... 2))/((lambda_(1)+lambda_(2))^(2))`

The two paricles A and B have de Broglie wavelengths 1 nm and 5 nm respectively if mass of A is four times the mass of B, the ratio of kinetic energie

Description : The two paricles A and B have de Broglie wavelengths 1 nm and 5 nm respectively if mass of A is four times the mass of B, the ratio of kinetic energie

Last Answer : The two paricles A and B have de Broglie wavelengths 1 nm and 5 nm respectively if mass of A is four times the mass of ... : 4` C. `20 : 1` D. `5 : 4`

Calculate the wavelengths of the member of Lyman, Balmer and Paschen series.

Description : Calculate the wavelengths of the member of Lyman, Balmer and Paschen series.

Last Answer : Calculate the wavelengths of the member of Lyman, Balmer and Paschen series.

A hydrogen like gas emits radiation of wavelengths `460 Å, 828 Å` and `1035Å`, only. Assume thar the atoms have only two excited states and the differ

Description : A hydrogen like gas emits radiation of wavelengths `460 Å, 828 Å` and `1035Å`, only. Assume thar the atoms have only two excited states and the differ

Last Answer : A hydrogen like gas emits radiation of wavelengths `460 Å, 828 Å` and `1035Å`, only. Assume ... of the ground state and the first excited state.

What wavelengths can astronomers detect from earth?

Description : What wavelengths can astronomers detect from earth?

Last Answer : Only those which aren't absorbed too much by the atmosphere.Those are visible light, and radio waves.

What is common unit of measurement for identifying visual wavelengths?

Description : What is common unit of measurement for identifying visual wavelengths?

Last Answer : nanometer

Lights of different colours are arranged below in order of increasing wavelengths: 1. Violet, indigo, blue 2. Green, orange, red 3. Red, green, indigo 4. Blue, green, yellow Which of the above are in proper sequence? (a) 1 only (b) 1 and 2 (c) 2 and 3 (d) 1 and 4

Description : Lights of different colours are arranged below in order of increasing wavelengths: 1. Violet, indigo, blue 2. Green, orange, red 3. Red, green, indigo 4. Blue, green, yellow Which of the above are in proper sequence? (a) 1 only (b) 1 and 2 (c) 2 and 3 (d) 1 and 4

Last Answer : Ans:(d)

The X –ray beam coming from an X-ray tube will be (a) Monochromatic (b) Having all wavelengths larger than a certain minimum wavelength (c) Having all wavelengths smaller than a certain maximum wavelength (d) Having all wavelengths between a minimum and a maximum wavelength

Description : The X –ray beam coming from an X-ray tube will be (a) Monochromatic (b) Having all wavelengths larger than a certain minimum wavelength (c) Having all wavelengths smaller than a certain maximum wavelength (d) Having all wavelengths between a minimum and a maximum wavelength

Last Answer : Ans:(b)

(3) checking the penetration of ultra-violet rays to the earth Explanation: Ozone in the ozone layer filters out sunlight wavelengths from about 200 nm UV rays to 315 nm, with ozone peak absorption at about 250 nm. This ozone UV absorption is important to life, since it extends the absorption of UV by ordinary oxygen and nitrogen in air (which absorbs all wavelengths < 200 nm) through the lower UV-C (200 nm-280 nm) and the entire UV-B band (280 nm-315 nm).

Description : (3) checking the penetration of ultra-violet rays to the earth Explanation: Ozone in the ozone layer filters out sunlight wavelengths from about 200 nm UV rays to 315 nm, with ozone peak absorption at about 250 nm. This ... the lower UV-C (200 nm-280 nm) and the entire UV-B band (280 nm-315 nm).

Last Answer : The advantage of detergents over soaps is – (1) Detergents are soluble in water (2) Detergents could not give much lather (3) Detergents give lather even with hard water (4) Soaps give lather with only soft water

(3) checking the penetration of ultra-violet rays to the earth Explanation: Ozone in the ozone layer filters out sunlight wavelengths from about 200 nm UV rays to 315 nm, with ozone peak absorption at about 250 nm. This ozone UV absorption is important to life, since it extends the absorption of UV by ordinary oxygen and nitrogen in air (which absorbs all wavelengths < 200 nm) through the lower UV-C (200 nm-280 nm) and the entire UV-B band (280 nm-315 nm).

Description : (3) checking the penetration of ultra-violet rays to the earth Explanation: Ozone in the ozone layer filters out sunlight wavelengths from about 200 nm UV rays to 315 nm, with ozone peak absorption at about 250 nm. This ... the lower UV-C (200 nm-280 nm) and the entire UV-B band (280 nm-315 nm).

Last Answer : The advantage of detergents over soaps is – (1) Detergents are soluble in water (2) Detergents could not give much lather (3) Detergents give lather even with hard water (4) Soaps give lather with only soft water

_____ is an antenna made up of a number of full wavelengths A. Elementary doublet B. Log-periodic C. Long wire D. Whip

Description : _____ is an antenna made up of a number of full wavelengths A. Elementary doublet B. Log-periodic C. Long wire D. Whip

Last Answer : C. Long wire

What are the electromagnetic radiations of wavelengths less than 300 angstroms? A. X-rays B. Ultraviolet rays C. Infrared D. Microwaves

Description : What are the electromagnetic radiations of wavelengths less than 300 angstroms? A. X-rays B. Ultraviolet rays C. Infrared D. Microwaves

Last Answer : A. X-rays

Oxygen molecule absorption peaks to electromagnetic wave are at what wavelengths? A. 1.35 cm and 1.7 mm B. 5 mm and 2.5 mm C. 5 cm and 2.5 cm D. 1.35 mm and 1.7 μm

Description : Oxygen molecule absorption peaks to electromagnetic wave are at what wavelengths? A. 1.35 cm and 1.7 mm B. 5 mm and 2.5 mm C. 5 cm and 2.5 cm D. 1.35 mm and 1.7 μm

Last Answer : B. 5 mm and 2.5 mm

Which of the following wavelengths where absorption of electromagnetic waves becomes peak due to vibrational resonances in the water vapor molecule? A. 1.35 cm and 1.7 mm B. 1.5 mm and 5 mm C. 1.35 dm and 1.7 cm D. 1.5 cm and 5mm

Description : Which of the following wavelengths where absorption of electromagnetic waves becomes peak due to vibrational resonances in the water vapor molecule? A. 1.35 cm and 1.7 mm B. 1.5 mm and 5 mm C. 1.35 dm and 1.7 cm D. 1.5 cm and 5mm

Last Answer : A. 1.35 cm and 1.7 mm

Oxygen molecule absorption peaks to electromagnetic wave are at what wavelengths? A. 1.35 mm and 1.7 μm B. 1.35 cm and 1.7 mm C. 5 cm and 2.5 cm D. 5 mm and 2.5 mm

Description : Oxygen molecule absorption peaks to electromagnetic wave are at what wavelengths? A. 1.35 mm and 1.7 μm B. 1.35 cm and 1.7 mm C. 5 cm and 2.5 cm D. 5 mm and 2.5 mm

Last Answer : D. 5 mm and 2.5 mm

Which of the following wavelengths where absorption of electromagnetic waves becomes peak due to vibrational resonances in the water vapor molecule? A. 1.35 cm and 1.7 mm B. 1.5 mm and 5mm C. 1.35 dm and 1.7cm D. 1.5 cm and 5 mm

Description : Which of the following wavelengths where absorption of electromagnetic waves becomes peak due to vibrational resonances in the water vapor molecule? A. 1.35 cm and 1.7 mm B. 1.5 mm and 5mm C. 1.35 dm and 1.7cm D. 1.5 cm and 5 mm

Last Answer : A. 1.35 cm and 1.7 mm

Two or more antennas separated by 9 wavelengths are used. A. Hybrid diversity B. Space diversity C. Polarized diversity D. Frequency diversity

Description : Two or more antennas separated by 9 wavelengths are used. A. Hybrid diversity B. Space diversity C. Polarized diversity D. Frequency diversity

Last Answer : B. Space diversity

Both Infrared and Microwave bands are invisible to the human eye. Then how are IR and microwave images from remote sensing satellites printed? How do they substitute the wavelengths?

Description : Both Infrared and Microwave bands are invisible to the human eye. Then how are IR and microwave images from remote sensing satellites printed? How do they substitute the wavelengths?

Last Answer : Both infrared and microwaves are part of the electromagnetic spectrum, which stretches from radio waves to gamma rays. each band of this spectrum corresponds to a small range of frequencies. Each ... levels) are finally printed on a computer screen as a picture or as a conventional photograph.

Very High Frequency (VHF) have ----- wavelengths? A. shorter (Answer) B. shortest

Description : Very High Frequency (VHF) have ----- wavelengths? A. shorter (Answer) B. shortest

Last Answer : A. shorter (Answer)

A body is called grey if the monochromatic emissivity of the body is (A) Zero (B) Unity (C) Same for all wavelengths (D) Different for all wavelengths

Description : A body is called grey if the monochromatic emissivity of the body is (A) Zero (B) Unity (C) Same for all wavelengths (D) Different for all wavelengths

Last Answer : (C) Same for all wavelengths

Thermal radiation is an electromagnetic radiation with wavelengths in _____ range.  A. 1 to 100 µm  B. 0.1 to 100 µm  C. 0.1 to 10 µm  D. 10 to 100 µm

Description : Thermal radiation is an electromagnetic radiation with wavelengths in _____ range.  A. 1 to 100 µm  B. 0.1 to 100 µm  C. 0.1 to 10 µm  D. 10 to 100 µm

Last Answer : 0.1 to 100 µm