यंग के द्वि-झिरी प्रयोग में, केन्द्रीय उच्चिष्ठ से पाँचवी दिप्त फ्रिन्ज की स्थिति \(5 \mathrm{~cm}\) है। झिरियों एवं पर्दे के बीच की दूरी \(1 \mathrm{~m}\) है, एवं \(600 \mathrm{~nm}\) तरंगदैर्ध्य वाला एक वर्णी प्रकाश प्रयुक्त किया जाता है, तो झिरियों के बीच की दूरी है :

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.