According to Wein's law:
1. = constant
2. = constant
3. = constant
4. = constant
A black body has a maximum wavelength at a temperature of 2000 K. Its corresponding wavelength at temperatures of 3000 K will be:
1. | \({3 \over 2} \lambda_m\) | 2. | \({2 \over 3} \lambda_m\) |
3. | \({4 \over 9} \lambda_m\) | 4. | \({9 \over 4} \lambda_m\) |
A black body at \(200\) K is found to emit maximum energy at a wavelength of \(14\) \(\mu \)m. When its temperature is raised to \(1000\) K, the wavelength at which maximum energy is emitted will be:
1. | \(14\) \(\mu \)m | 2. | \(70\) \(\mu \)m |
3. | \(2.8\) \(\mu \)m | 4. | \(2.8\) nm |
What is the ratio of the temperatures \(T_{1}\)
1. \(3:2\)
2. \(2:1\)
3. \(4:3\)
4. \(1:1\)
A piece of iron is heated in a flame. If it becomes dull red first, then becomes reddish yellow, and finally turns to white hot, the correct explanation for the above observation is possible by using:
1. | Stefan's law | 2. | Wien's displacement law |
3. | Kirchhoff's law | 4. | Newton's law of cooling |
If is the wavelength, corresponding to which the radiant intensity of a block is at its maximum and its absolute temperature is T, then which of the following graph correctly represents the variation of T?
1. | 2. | ||
3. | 4. |
Three stars \(A,\) \(B,\) and \(C\) have surface temperatures \(T_A,~T_B\) and \(T_C\) respectively. Star \(A\) appears bluish, star \(B\) appears reddish and star \(C\) yellowish. Hence,
1. | \(T_A>T_B>T_C\) | 2. | \(T_B>T_C>T_A\) |
3. | \(T_C>T_B>T_A\) | 4. | \(T_A>T_C>T_B\) |
The plots of intensity versus wavelength for three black bodies at temperatures , and respectively are as shown. Their temperatures are such that:
1. | \(\mathrm{T}_1>\mathrm{T}_2>\mathrm{T}_3 \) | 2. | \(\mathrm{T}_1>\mathrm{T}_3>\mathrm{T}_2 \) |
3. | \(\mathrm{T}_2>\mathrm{T}_3>\mathrm{T}_1 \) | 4. | \(\mathrm{T}_3>\mathrm{T}_2>\mathrm{T}_1\) |
The energy distribution E with the wavelength for the black body radiation at temperature T Kelvin is shown in the figure. As the temperature is increased the maxima will:
1. | Shift towards left and become higher |
2. | Rise high but will not shift |
3. | Shift towards right and become higher |
4. | Shift towards left and the curve will become broader |
A black body is at a temperature of 5760 K. The energy of radiation emitted by the body at a wavelength of 250 nm is U1, at a wavelength of 500 nm is U2 and that at 1000 nm is U3. Given Wien's constant of the following is correct?
1. U3=0
2. U1>U2
3. U2>U1
4. U1=0