which of the following is close to an ideal black body

Which of the following is close to an ideal black body ?

A. Black lamp

B. Cavity maintained at constant temperature

C. Platinum black

D. A lamp of charcoal heated to high temperature

Answer : Cavity maintained at constant temperature

Solution :
Materials like black velvet or lamp black come close to ideal black bodies, but the best practical realization of an ideal black body is a small hole leading into a cavity maintained at constant temperature as this absorbs $$98\% $$ of the radiation incident on them. Cavity approximating an ideal black body is shown in the figure. Radiation entering the cavity has little chance of leaving before it is completely absorbed.

Releted MCQ Question on
Heat and Thermodynamics >> Radiation

Releted Question 1

Two metallic spheres $${S_1}$$ and $${S_2}$$ are made of the same material and have got identical surface finish. The mass of $${S_1}$$ is thrice that of $${S_2}.$$ Both the spheres are heated to the same high temperature and placed in the same room having lower temperature but are thermally insulated from each other. The ratio of the initial rate of cooling of $${S_1}$$ to that of $${S_2}$$ is

A. $$\frac{1}{3}$$

B. $${\frac{1}{{\sqrt 3 }}}$$

C. $${\frac{{\sqrt 3 }}{1}}$$

D. $${\left( {\frac{1}{3}} \right)^{\frac{1}{3}}}$$

View Answer

Releted Question 2

A spherical black body with a radius of $$12\,cm$$ radiates 450 $$W$$ power at 500 $$K.$$ if the radius were halved and the temperature doubled, the power radiated in watt would be

A. 225

B. 450

C. 900

D. 1800

View Answer

Releted Question 3

A spherical black body with a radius of $$12\,cm$$ radiates $$450\,W$$ power at 500 $$K.$$ If the radius were halved and the temperature doubled, the power radiated in watt would be

A. 225

B. 450

C. 900

D. 1800

View Answer

Releted Question 4

The plots of intensity versus wavelength for three black bodies at temperature $${T_1},$$ $${T_2}$$ and $${T_3}$$ respectively are as shown. Their temperatures are such that

A. $${T_1} > {T_2} > {T_3}$$

B. $${T_1} > {T_3} > {T_2}$$

C. $${T_2} > {T_3} > {T_1}$$

D. $${T_3} > {T_2} > {T_1}$$

View Answer

Which of the following is close to an ideal black body ?

Releted MCQ Question on
Heat and Thermodynamics >> Radiation

A spherical black body with a radius of $$12\,cm$$ radiates 450 $$W$$ power at 500 $$K.$$ if the radius were halved and the temperature doubled, the power radiated in watt would be

A spherical black body with a radius of $$12\,cm$$ radiates $$450\,W$$ power at 500 $$K.$$ If the radius were halved and the temperature doubled, the power radiated in watt would be

The plots of intensity versus wavelength for three black bodies at temperature $${T_1},$$ $${T_2}$$ and $${T_3}$$ respectively are as shown. Their temperatures are such that

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Radiation

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Which of the following is close to an ideal black body ?

Releted MCQ Question on Heat and Thermodynamics >> Radiation

A spherical black body with a radius of $$12\,cm$$ radiates 450 $$W$$ power at 500 $$K.$$ if the radius were halved and the temperature doubled, the power radiated in watt would be

A spherical black body with a radius of $$12\,cm$$ radiates $$450\,W$$ power at 500 $$K.$$ If the radius were halved and the temperature doubled, the power radiated in watt would be

The plots of intensity versus wavelength for three black bodies at temperature $${T_1},$$ $${T_2}$$ and $${T_3}$$ respectively are as shown. Their temperatures are such that

Practice More Releted MCQ Question on Radiation

Practice More MCQ Question on Physics Section

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Heat and Thermodynamics >> Radiation

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Radiation