149481 The wavelength of the radiation emitted by a black body is $1 \mathrm{~mm}$ and Wien's constant is $3 \times$ $10^{-3} \mathrm{mK}$. Then the temperature of the black body will be

149484 A solid cylinder of radius $r_{1}=2.5 \mathrm{~cm}$, length $I_{1}$ $=5.0 \mathrm{~cm}$ and temperature $40^{\circ} \mathrm{C}$ is suspended in an environment of temperature $60^{\circ} \mathrm{C}$. The thermal radiation transfer rate for cylinder is 1.0 W. If the cylinder is stretched until its radius becomes $r_{2}=0.50 \mathrm{~cm}$, the thermal radiation transfer rate is changed to

149487 A black body at a temperature $T$ radiates energy at the rate of $E W \mathrm{~m}^{-2}$. If its temperature is decreased by $\left(\frac{T}{2}\right)$, the energy radiated will be

149483 Assertion A thermos bottle consists of a double walled glass vessel with the space between the two walls evacuated, so that the heat transfer between the contents of the bottle and outside is minimised.
Reason The vacuum between the two walls inhibits the heat transfer by radiation mechanism. Which of the following is correct?

149481 The wavelength of the radiation emitted by a black body is $1 \mathrm{~mm}$ and Wien's constant is $3 \times$ $10^{-3} \mathrm{mK}$. Then the temperature of the black body will be

149484 A solid cylinder of radius $r_{1}=2.5 \mathrm{~cm}$, length $I_{1}$ $=5.0 \mathrm{~cm}$ and temperature $40^{\circ} \mathrm{C}$ is suspended in an environment of temperature $60^{\circ} \mathrm{C}$. The thermal radiation transfer rate for cylinder is 1.0 W. If the cylinder is stretched until its radius becomes $r_{2}=0.50 \mathrm{~cm}$, the thermal radiation transfer rate is changed to

149487 A black body at a temperature $T$ radiates energy at the rate of $E W \mathrm{~m}^{-2}$. If its temperature is decreased by $\left(\frac{T}{2}\right)$, the energy radiated will be

149483 Assertion A thermos bottle consists of a double walled glass vessel with the space between the two walls evacuated, so that the heat transfer between the contents of the bottle and outside is minimised.
Reason The vacuum between the two walls inhibits the heat transfer by radiation mechanism. Which of the following is correct?

149481 The wavelength of the radiation emitted by a black body is $1 \mathrm{~mm}$ and Wien's constant is $3 \times$ $10^{-3} \mathrm{mK}$. Then the temperature of the black body will be

149484 A solid cylinder of radius $r_{1}=2.5 \mathrm{~cm}$, length $I_{1}$ $=5.0 \mathrm{~cm}$ and temperature $40^{\circ} \mathrm{C}$ is suspended in an environment of temperature $60^{\circ} \mathrm{C}$. The thermal radiation transfer rate for cylinder is 1.0 W. If the cylinder is stretched until its radius becomes $r_{2}=0.50 \mathrm{~cm}$, the thermal radiation transfer rate is changed to

149487 A black body at a temperature $T$ radiates energy at the rate of $E W \mathrm{~m}^{-2}$. If its temperature is decreased by $\left(\frac{T}{2}\right)$, the energy radiated will be

149483 Assertion A thermos bottle consists of a double walled glass vessel with the space between the two walls evacuated, so that the heat transfer between the contents of the bottle and outside is minimised.
Reason The vacuum between the two walls inhibits the heat transfer by radiation mechanism. Which of the following is correct?

149481 The wavelength of the radiation emitted by a black body is $1 \mathrm{~mm}$ and Wien's constant is $3 \times$ $10^{-3} \mathrm{mK}$. Then the temperature of the black body will be

149484 A solid cylinder of radius $r_{1}=2.5 \mathrm{~cm}$, length $I_{1}$ $=5.0 \mathrm{~cm}$ and temperature $40^{\circ} \mathrm{C}$ is suspended in an environment of temperature $60^{\circ} \mathrm{C}$. The thermal radiation transfer rate for cylinder is 1.0 W. If the cylinder is stretched until its radius becomes $r_{2}=0.50 \mathrm{~cm}$, the thermal radiation transfer rate is changed to

149487 A black body at a temperature $T$ radiates energy at the rate of $E W \mathrm{~m}^{-2}$. If its temperature is decreased by $\left(\frac{T}{2}\right)$, the energy radiated will be

149483 Assertion A thermos bottle consists of a double walled glass vessel with the space between the two walls evacuated, so that the heat transfer between the contents of the bottle and outside is minimised.
Reason The vacuum between the two walls inhibits the heat transfer by radiation mechanism. Which of the following is correct?