Thermal Energy and Heat Transfer

The wavelength of maximum intensity for emitted radiation from a source is $11\times {10}^{-5} \mathrm{cm}$.  The temperature of this source is $n$ times the temperature of some other source for which the wavelength at maximum intensity is known to be $5.5\times {10}^{-5} \mathrm{cm}$. Find the value of $n$.

A black body is at temperature $2880 \mathrm{K}$. The energy of radiation emitted by the body at wavelength $250 \mathrm{nm}$ is $U_1$, at wavelength $500 \mathrm{nm}$ is $U_2$ and that of $1000 \mathrm{nm}$ is $U_3$. Then the correct answer is $($Weins constant $\left.b=2.88\times {10}^6 \mathrm{nmK}\right)$

The climate of the place is affected by its distance from the sea.

Explain how liquids and gases are heated?

Choose the correct word from the following options:

Land and sea breezes are caused due to:-

The formula${\lambda }_{m}T = 0.29 \mathrm{cm} \mathrm{K}$is used to obtain the characteristic temperature ranges for different parts of the electromagnetic spectrum. Find the value of temperature(in $\mathrm{K}$) for ${\lambda }_m=5\times {10}^{-5} \mathrm{cm}$.

A black body emits radiations of maximum intensity at $5000 \stackrel{\circ }{\mathrm{A}}$ when its temperature is $1227°\mathrm{C}$. If, its temperature is increased by $1000°\mathrm{C}$  then the maximum intensity of emitted radiation will be at:

The wavelength of maximum intensity of radiation emitted by a star is $289.8\mathrm{ }\mathrm{n}\mathrm{m}$. The radiation intensity of the star is
(Stefan's constant $=5.67\times {10}^{-8} \mathrm{W} {\mathrm{m}}^{-2} {\mathrm{K}}^{-4},$Wien's constant $=b=2898\mathrm{ }\mathrm{\mu }\mathrm{m}\mathrm{ }\mathrm{K}$) 

Experimental investigation shows that the intensity of solar radiation is maximum for a wavelength $480 \mathrm{nm}$ in the visible region. Estimate the surface temperature of sun. (Given Wien's constant $b=2.88\times {10}^{-3} \mathrm{m}\mathrm{ }\mathrm{K}$)

Generally the temperature of a distant star is estimated using

The earth radiates in the infra-red region of the spectrum. The spectrum is correctly given by

The black body spectrum of an object $Q_1$ is such that its radiant intensity (i.e., intensity per unit wavelength interval) is maximum at a wavelength of 100 nm. Another object $O_2$ has the maximum radiant intensity at 600 nm. The ratio of power emitted per unit area by source $O_1$ to that of source $O_2$ is

According to Wien's law

A black body is at a temperature of $5760 \mathrm{K}$. The energy of radiation emitted by the body at wavelength $250 \mathrm{nm}$ is $U_1$ , at wavelength $500 \mathrm{nm}$ is $U_2$ and that at $1000 \mathrm{nm}$ is $U_3$ . Wien's constant, $b=2.88\times {10}^6 \mathrm{nmK}$. Which of the following is correct?

Following graphs show the variation in the intensity of heat radiations by the black body and frequency at a fixed temperature. Choose the correct option.

The spectral energy distribution of the Sun (temperature$=6050 \mathrm{K}$) has a maximum at $4753 \mathrm{\AA }$. The temperature of a star for which this maximum is at $9506 \mathrm{\AA }$ is

Following graph shows the correct variation in intensity of heat radiations by black body and frequency at a fixed temperature

Following graph shows the correct variation in intensity of heat radiations by black body and frequency at a fixed temperature

On observing light from three different stars P,Q and R, it was found that intensity of violet colour is maximum in the spectrum of P, the intensity of green colour is maximum in the spectrum of R and the intensity of red colour is maximum in the spectrum of Q. If ${\mathrm{T}}_{\mathrm{p}},\mathrm{ }{\mathrm{T}}_{\mathrm{Q}}$ and ${\mathrm{T}}_{\mathrm{R}}$ are the respective absolute temperatures of P, Q and R, then it can be concluded from the above observations that :

Assertion: The temperature of a red-hot body is lower than that of a white-hot body.

Reason: This follows from Wien's displacement law $:\mathrm{ }{\mathrm{\lambda }}_{\mathrm{m}}\mathrm{ }.\mathrm{ }\mathrm{T}\mathrm{ }=\mathrm{ }\mathrm{c}\mathrm{o}\mathrm{n}\mathrm{s}\mathrm{t}\mathrm{a}\mathrm{n}\mathrm{t}$ .