Wien's Displacement Law

Q.

For an ideal heat engine, the temperature of the source is $127$$º\mathrm{C}$. In order to have $60$$\%$ efficiency, the temperature of the sink should be ________ºC. (Round off to the Nearest Integer)

Q.

The energy spectrum of a blackbody exhibits a maximum around a wavelength ${\lambda }_0$. The temperature of the black body is now changed such that the energy is maximum around a wavelength $\frac{3{\lambda }_0}{4}$ The power radiated by the blackbody will now increase by a factor:

1. 4/3

2. None

3. 256/81

4. 16/9

Q.

Electromagnetic radiation has an energy of $13.2keV$. Then, the radiation belongs to the region of

1. Visible light

2. Ultraviolet

3. Infrared

4. $X$- rays

Q. If at temperature $T_1=1000K$, the wavelength is $1.4\times {10}^{-6}m$, then at what temperature the wavelength will be $2.8\times {10}^{-6}m$

1. 2000 K
2. 500 K
3. 250 K
4. None of these

Q.

Variation of radiant energy emitted by sun, filament of tungsten lamp and welding arc as a function of its wavelength is shown in figure. Which of the following option is the correct match? (IIT JEE 2005)

1. Sun - T₂, tungsten filament - T₁, welding are - T₃

2. Sun - T₃, tungsten filament - T₁, welding are - T₂

3. Sun - T₃, tungsten filament - T₂, welding are - T₁

4. Sun - T₁, tungsten filament - T₂, welding are - T₃