# When radius of a conducting wire is increased, its specific resistance-

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When radius of a conducting wire is increased, its specific resistance-
1. decreases
2. increases
3. does not change
4. first increases and then decreases

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Correct Answer - Option 3 : does not change

The correct answer is option 3) i.e. does not change

CONCEPT:

• Resistance: The hindrance to the flow of current offered by a material is called electrical resistance.
• The SI unit of electrical resistance is ohm (Ω). The resistance of a conducting wire is given by the equation:

$R = ρ\frac{l}{A}$

Where R is the resistance, l is the length of the wire and A is the cross-sectional area of the material.

• The resistivity (ρ of a material is defined as the resistance offered by a material of unit cross-sectional area and unit length
• Resistivity is an intrinsic property i.e. it is the same for a given type of material.

EXPLANATION:

• Specific resistance is defined as the resistance offered by a unit length. It is also known as resistivity.
• Since specific resistance is an intrinsic property, a change in the radius of the wire will not change its value.
• Hence, specific resistance does not change.