List I (Spectral Lines of Hydrogen for transitions from) | List II (Wavelength (nm)) | ||
A. | n2 = 3 to n1 = 2 | I. | 410.2 |
B. | n2 = 4 to n1 = 2 | II. | 434.1 |
C. | n2 = 5 to n1 = 2 | III. | 656.3 |
D. | n2 = 6 to n1 = 2 | IV. | 486.1 |
Step 1: Recall the Balmer Series Formula
The Balmer series describes transitions to \( n_1 = 2 \) in the hydrogen atom. The wavelength of emitted light is given by:
$$ \frac{1}{\lambda} = R \left( \frac{1}{n_1^2} - \frac{1}{n_2^2} \right) $$
Where:
\(\lambda\) = Wavelength of emitted light
R = Rydberg constant
n₁ = Lower energy level (\( n_1 = 2 \) for the Balmer series)
n₂ = Higher energy level (\( n_2 > 2 \))
Step 2: Match Wavelengths
Using known values of wavelengths for each transition:
\( n_2 = 3 \rightarrow n_1 = 2 \) : 656.3 nm → (A-III)
\( n_2 = 4 \rightarrow n_1 = 2 \) : 486.1 nm → (B-IV)
\( n_2 = 5 \rightarrow n_1 = 2 \) : 434.1 nm → (C-II)
\( n_2 = 6 \rightarrow n_1 = 2 \) : 410.2 nm → (D-I)
Step 3: Conclusion
The correct matching is:
A-III
B-IV
C-II
D-I
Given below are two statements:
Statement (I) : The dimensions of Planck’s constant and angular momentum are same.
Statement (II) : In Bohr’s model, electron revolves around the nucleus in those orbits for which angular momentum is an integral multiple of Planck’s constant.
In the light of the above statements, choose the most appropriate answer from the options given below:
The current passing through the battery in the given circuit, is:
Three identical heat conducting rods are connected in series as shown in the figure. The rods on the sides have thermal conductivity 2K while that in the middle has thermal conductivity K. The left end of the combination is maintained at temperature 3T and the right end at T. The rods are thermally insulated from outside. In steady state, temperature at the left junction is \(T_1\) and that at the right junction is \(T_2\). The ratio \(T_1 / T_2\) is