यंग के द्विझिरी प्रयोग में, दो बिन्दुओं पर तीव्रताएँ क्रमशः \(I_1\) तथा \(I_2\) है जहाँ पथान्तर क्रमशः \(\frac{\lambda}{4}\) व \(\frac{\lambda}{3}\) ( \(\lambda\) प्रयुक्त प्रकाश की तरंगदैर्ध्य) है। यदि प्रत्येक झिरी से उत्पन्न तीव्रता \(\mathrm{I}_0\) से प्रद्रर्शित की गई हो तब \(\frac{\mathrm{I}_1+\mathrm{I}_2}{\mathrm{I}_0}=\ldots \ldots .\). होगा।

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.