Match the temperature of a black body given in List-$I$ with an appropriate statement in List-$II$, and…

Match the temperature of a black body given in List-$I$ with an appropriate statement in List-$II$, and choose the correct option. [Given: Wien’s constant as $2.9 \times 10^{-3} mK$ and $\frac{hc}{e}=1.24 \times 10^{-6} Vm$] $\begin{aligned} &\begin{array}{|c|c|c|c|} \hline & \text { List-I } & & \text { List-II } \\ \hline \mathbf{P} & 2000 \mathrm{~K} & 1 & \begin{array}{l} \text { The radiation at peak wavelength can lead to emission of } \\ \text { photoelectrons from a metal of work function } 4 \mathrm{eV} \end{array} \\ \hline \text { Q } & 3000 \mathrm{~K} & 2 & \text { The radiation at peak wavelength is visible to human eye } \\ \hline \text { R } & 5000 \mathrm{~K} & 3 & \begin{array}{l} \text { The radiation at peak emission wavelength will result in the } \\ \text { widest central maximum of a single slit diffraction } \end{array} \\ \hline \mathbf{S} & 10000 \mathrm{~K} & 4 & \begin{array}{l} \text { The power emitted per unit area is } \frac{1}{16} \text { of that emitted by a } \\ \text { blackbody at temperature } 6000 \mathrm{~K} \end{array} \\ \hline & & 5 & \begin{array}{l} \text { The radiation at peak emission wavelength can be used to } \\ \text { image human bones } \end{array} \\ \hline \end{array} \end{aligned}$
  1. P3, Q5, R2, S3
  2. P3, Q2, R4, S1
  3. P3, Q4, R2, S1
  4. P1, Q2, R5, S3

Solution

Maximum wavelength for each case:

P 2000 K

λmT=b

λm=bT=2.9×10-32000=1.45×10-6 m=1450 nm

(Q) 3000 K λmT=bλm=2.9×10-33000=966.66 nm
(R) 5000 K λmT=bλm=2.9×10-35000=580 nm
(S) 10000 K λmT=bλm=2.9×10-310,000=290 nm

Now for List-II:

1 λth=hcϕ=1.24×10-64=0.31×10-6 m=310 nm

For λλth, emission of photoelectrons will take place. Therefore, S1.

2 Wavelength range visible to human eye ranges from 400 to 700 nm. Therefore, R2.

3 Width of the central maxima is directly proportional to the wavelength of the light used. Therefore, for maximum width, maximum wavelength is required. Hence, P3.

4 Power emitted by blackbody is given by, 

σT14=116σT42T1=12T2=3000 K

Therefore, Q4.

5 For imaging bones X-rays are used in the wavelength range of 1-10 nm. None of the options in List-I matches with it.

`

Asked in: JEE Advanced 2023 (Paper 1)

Practice more Kinetic Theory of Gases and Radiation questions on Aicharya