Relation between Current and Drift Velocity: Practice Problem & Solution
Assertion (A): As a wire is stretched to four times its length, its resistivity becomes four times, such that resistance also increases. Reason (R): \( R = \frac{\rho A}{l} \) where symbols have their usual meaning.
Solution Explained:
To solve this problem, we apply the core principles of Relation between Current and Drift Velocity. Understanding the underlying formula is key to arriving at the correct answer below:
Assertion (A) is false because resistivity is an intrinsic property of the material and does not change with stretching, only resistance changes. Reason (R) is false because the correct formula for resistance is \( R = \frac{\rho l}{A} \).
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