A heated body emits radiation which has maximum intensity at frequency fₘ . If temperature of body

English

Gujarati

Hindi

10-2.Transmission of Heat

normal

A heated body emits radiation which has maximum intensity at frequency $f_m$. If the temperature of the body is doubled

A

The maximum intesity radiation will be at frequency $2f_m$

B

The maximum intesity radiation will be at frequency $\frac{1}{2}\,{f_m}$

C

The total emitted energy will increase to $2\, times$

D

The total emitted energy will increase to $8\, times$.

Solution

$\lambda_{\max }=\frac{b}{T} \Rightarrow \lambda_{\max }=\frac{c}{f_{\max }}=\frac{b}{T} \quad\left\{\because \lambda=\frac{c}{f}\right\}$

$\frac{\mathrm{cT}}{\mathrm{b}}=\mathrm{f}_{\mathrm{max}} \Rightarrow \mathrm{f}_{\mathrm{max}} \propto \mathrm{T} \quad$ so

on doubling temperature $\mathrm{f}_{\mathrm{max}}$ doubles Emitted

$\mathrm{Q}=\mathrm{e}_{\mathrm{x}} \sigma \mathrm{AT}^{4} \mathrm{t} \quad \Rightarrow \quad \mathrm{Q} \propto \mathrm{T}^{4}$

So $Q$ becomes $16$ times

Standard 11

Physics

Share

Similar Questions

Two large holes are cut in a metal sheet. If this is heated, distances $AB$ and $BC$, (as shown)

normal

Which of the following cylindrical rods will coduct most heat when their ends are maintained at the same steady temperatures?

normal

The maximum energy in the thermal radiation from a hot source occurs at a wavelength of $11\times10^{-5}\, cm$. According to Wien's law, the temperature of the source (on kelvin scale) will be n times the temperature of another source (on Kelvin scale) for which the wavelength at maximum energy is $5.5\times10^{-5}\, cm$. The value of $n$ is

normal

A black metal foil is warmed by radiation from a small sphere at temperature $' T'$ and at a distance $' d'$ . It is found that the power received by the foil is $P$ . If both the temperature and distance are doubled, the power received by the foil will be :

normal

A cylinder of radius $R$ made of a material of thermal conductivity $K_1$ is surrounded by a cylindrical shell of inner radius $R$ and outer radius $2R$ made of material of thermal conductivity $K_2$ . The two ends of the combined system are maintained at two different temperatures. There is no loss of heat across the cylindrical surface and the system is in steady state. The effective thermal conductivity of the system is

normal