Assertion (A): Bending a wire does not affect electrical resistance.

Reason (R): Resistance of wire is proportional to resistivity of material.

 

Answer:

Resistance of wire, R = ρ (l / A)        —----(i)

Where,

  • ρ is the resistivity
  • l is the length of the wire.
  • A is the area of cross-section of the wire. 

When a wire is bent, 

  • Resistivity - doesn’t change
  • Length - doesn’t change
  • Area of cross-section - doesn’t change. 

Hence, bending a wire does not affect the resistance of a wire.

From equation (i), it is clear that Resistance is directly proportional to resistivity.

Thus,

  • Assertion is true.
  • Reasoning is true.

So, the correct answer is (a).

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Transcript

Question 2 Assertion (A): Bending a wire does not affect electrical resistance. Reason (R): Resistance of wire is proportional to resistivity of material. Resistance of wire, R = "ρ" (𝑰/𝑨) Where, ρ is the resistivity l is the length of the wire. A is the area of cross-section of the wire. When a wire is bent, Resistivity - doesn’t change Length - doesn’t change Area of cross-section - doesn’t change. Hence, bending a wire does not affect the resistance of a wire.From equation (i), it is clear that Resistance is directly proportional to resistivity. Thus, Assertion is true. Reasoning is true. So, the correct answer is (a)

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CA Maninder Singh is a Chartered Accountant for the past 14 years and a teacher from the past 18 years. He teaches Science, Economics, Accounting and English at Teachoo