\(25.0 \mathrm{~mm}^2\) के अनुपृस्थ परिच्छेद क्षेत्रफल के एकतार में \(2 \mathrm{~A}\) की एक धारा प्रवाहित होती है। एक घन मीटर में मुक्त इलैक्ट्रानों की संख्या \(2.0 \times 10^{28}\) है। इलैक्ट्रानों का अनुगमन वेग_______ \(\times 10^{-6} \mathrm{~ms}^{-1}\) है (दिया है, इलैक्ट्रान पर आवेश \(=1.6 \times 10^{-19} \mathrm{C}\) )।

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.