Q 1 :    

Match List I with List II

	LIST I (Spectral Series for Hydrogen)		LIST II (Spectral Region/Higher Energy State)
A.	Lyman	I.	Infrared region
B.	Balmer	II.	UV region
C.	Paschen	III.	Infrared region
D.	Pfund	IV.	Visible region

 

Choose the correct answer from the options given below:               [2024]

• A-I, B-III, C-II, D-IV

   

• A-II, B-III, C-I, D-IV

   

• A-II, B-IV, C-III, D-I

   

• A-I, B-II, C-III, D-IV

   

Q 2 :    

Number of spectral lines obtained in $H{e}^{+}$ spectra, when an electron makes transition from fifth excited state to first excited state will be _______ .             [2024]

Q 3 :    

Given below are two statements:

Statement I: A spectral line will be observed for a $2p_x\to 2p_y$ transition.

Statement II: $2p_x$ and $2p_y$ are degenerate orbitals.

In the light of the above statements, choose the correct answer from the options given below:                 [2025]

• Both Statement I and Statement II are true

   

• Statement I is true but Statement II is false

   

• Both Statement I and Statement II are false

   

• Statement I is false but Statement II is true

   

Q 4 :    

Heat treatment of muscular pain involves radiation of wavelength of about 900 nm. Which spectral line of H atom is suitable for this? 

Given: Rydberg constant $R_H={10}^5 {\text{cm}}^{-1}\text{,}$ $h=6.6\times {10}^{-34}\text{Js,}$ $c=3\times {10}^8\text{m/s}$                  [2025]

• Lyman series, $\infty \to 1$

   

• Balmer series, $\infty \to 2$

   

• Paschen series, $5\to 3$

   

• Paschen series, $\infty \to 3$