कोई वस्तु ' \(o\) ' किसी अवतल दर्पण के समक्ष चित्र में दिखाए अनुसार रखी है, जिसके वक्र की त्रिज्या \(200\,cm\) है। वस्तु, दर्पण की तरफ \(2\,cm / s\) की चाल से चलना शुरू करती है। \(10\,s\) बाद, प्रतिबिम्ब की स्थिति दर्पण से \(.......\,cm\) दूर होगी।

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.