CUET · PHYSICS · PYQ PAPER 2023

An electron in a hydrogen atom is in the third excited state. It returns to the ground state by emitting photons. How many different photon wavelengths are possible ?

Verified Solution

Answer & Solution

Correct Answer

(B) 6

Step-by-step Solution

Detailed explanation

Initial state: \( n = 3 + 1 = 4 \) Number of possible transitions \( N = \frac{n(n-1)}{2} \) \( N = \frac{4(4-1)}{2} = \frac{4 \times 3}{2} = 6 \)

Apply the relevant identity from the chapter and substitute the values established in the previous step, keeping the original constraint in view.

Use the simplified expression to isolate the unknown, then plug the result back into the question setup to confirm the working is internally consistent.

Cross-check against a boundary or limiting case. Both the dimensional balance and the qualitative behaviour at the extreme should agree with the candidate answer.

Combine the steps above to identify the correct option. The remaining choices each fail at least one of the consistency, dimensional, or boundary checks.

Same subject

Explore more questions on app

From CUET

Match List - I with List - II

List - I (Cell Type)	List - II (Characteristic/Reaction)
A. Fuel Cell	I. Rechargeable
B. Mercury Cell	II. Reaction at anode, \(\text{Zn} \rightarrow \text{Zn}^{2+} + 2\text{e}^{-}\)
C. Leclanche Cell	III. Cell reaction \(2\text{H}_2 + \text{O}_2 \rightarrow 2\text{H}_2\text{O}\)
D. Ni-Cd Cell	IV. Gives steady potential

Choose the correct answer from the options given below :

CUET 2023 Medium

Which of the following functions from \(Z\) to \(Z\) is a bijective function? (where \(Z\) is set of integers)

CUET 2025 Hard

Explore more questions on app