Why does a good emitter of heat radiation appear black at room temperature?

Q: As an object is heated, the peak in its thermal emission spectrum may shift out of the visible part…

A: According to Wien's displacement law λT=a constant

Q: Discuss the scientific properties of why the sky is blue.

A: The blue color of sky:

Q: Look at your red , sunburned feet when they are under water. Why don’t they look as red as they are…

A: Ray of light coming from red wound will undergo scattering and refraction both at water surface.

Q: Why does the color of a surface affect emissivity?

A: Emissivity of the surface of a colored body is the body's effectiveness to radiate thermal energy.…

Q: Is it necessary that that every black coloured objects should be considered a blackbody?

A: A perfect black body is a body that absorbs all the radiation that falls on it.

Q: For a blackbody object of given volume, which shape will it emit the least radiation? Why?

A:

Q: Why are infrared waves often called heat waves?

A:

Q: could a light bulb approximate a blackbody?

A: Black body absorbs radiation of all wavelength which are incident on it. Black body does not reflect…

Q: Why does a white piece of paper appear white in white light, red in red light, blue in blue light,…

A: A piece of paper that appears white in sunlight has the property of reflecting any color that is…

Q: It is hotter at the same distance over the top of a fire than in front of it, Why?

A: Whenever we put fire at a place, the air surrounding the fire gets heated up. As we know that hot…

Q: Lamp black and platinum black are used as perfect black body one for the absorption of heat…

A: an ideal black body , which absorbs all types of radiations falls on it. this is true for the…

Q: Ultraviolet radiation can be helpful and harmful at the same time. What should someone do to avoid…

A: Step1: Overview Ultraviolet radiation is electromagnetic radiation emitted by the sun and several…

Q: How is Ultraviolet Light used?

A: UV radiation is widely used in industrial processes and in medical and dental practices for a…

Q: When something is painted red, what color is most absorbed?

A:

Q: How would the whiteness of snow appear if Earth's atmosphere were several times denser?

A: According to the Rayleigh scattering, the dispersion is greater at lower wavelengths (higher…

Q: Why does light striking a metal surface eject only electrons, not protons?

A: Electrons take less energy to come out of the metal. Electrons move freely in a metal.

Q: Distinguish between emissive power and spectral emissive power.

A: When any thermal radiation is radiated from a unit surface area, the rate at which it is radiated at…

Q: Why does a fireplace poker appear black when not in the fire and red, yellow, or white when left in…

A:

Q: Very big particles, like droplets of water, absorb more radiation than they scatter. How does this…

A: Scattering means the change in the  direction of particles due to collisions of two or more…

Q: s blocked by the black shap is used?

A: When light travel into a medium with a higher index of refraction, the light bends towards the…

Q: Ultraviolet light causes sunburn whereas visible light even of greater intensity, does not? Why is…

A: Ultraviolet radiation is the main cause of sunburns. They can change the DNA in skin cells directly.…

Q: If you were to subject a green ink to paper chromatographic separation, what are the possible colors…

A:

Q: How does the ditrection of polarization of light compare with the direction of vibration of the…

A:

Q: which warms more quickly in sunlight -a colourless or coloured piece of glass? Also explain Why?

A: A coloured glass can absorb all the colours except its own colour while the colourless glass can’t…

Q: What determines whether a material is transparent or opaque?

A:

Q: The air in a dark, smoky room often looks bluish when illuminated by white light. What creates this…

A: Given statement : "The air in a dark, smoky room often looks bluish when illuminated by white light"…

Q: Why does the blood of injured deep-sea divers look greenish-black in underwater photographs taken…

A: Natural light at low depths of the ocean is blue due to the filtering effect of a water above. There…

Q: A body with large reflectivity is a poor emitter, Why?

A: According to Kirchhoff's law, a poor absorber of heat is a poor emitter. Hence, a body with large…

Q: Red sun rise occurs for the same reason as red sunsets. But sunsets are usually more colourful than…

A: The light from the sun travels through Earth’s atmosphere it undergoes scattering before it reaches…

Q: When an object is painted red, what color is absorbed most?

A: When an object is painted red, it looks red because the molecules in the paint have absorbed the…

Q: If the sunlight were somehow green in color instead of white, what color clothing would be advisable…

A: Since green color will absorb all color frequencies except green so when sunlight of green color…

Q: Sunlight, considered to be white, actually appears to be a bit yellow. Why?

A: The phenomenon in which the light rays deviates from its original straight path by striking  on…

Q: What are the benefits of ultraviolet rays?

A: Ultraviolet rays are a form of electromagnetic radiation. Ultraviolet Light refers to the region of…

Q: Ultraviolet light causes sunburns, whereas visible light, even of greater intensity, does not. Why…

A: The frequency of Ultraviolet light is greater than the visible light. The frequency of…

Wien's displacement law

Students often get confused between Wien's displacement law and Planck's radiation law. Although both are historically related, yet they are conceptually different. Planck's law helps determine the spectrum of a blackbody, while Wien's law determines the relationship between peak wavelength and temperature.