Which one of the following physical quantities does NOT affect the res

Which one of the following physical quantities does NOT affect the resistance of a cylindrical resistor ?

The current through it

Its length

The resistivity of the material used in the resistor

The area of cross-section of the cylinder

Answer is Right!

Answer is Wrong!

This question was previously asked in

UPSC NDA-1 – 2017

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The current through the cylindrical resistor does NOT affect its resistance.

The resistance of a resistor is a property of the material and its geometry. For a cylindrical resistor made of a homogeneous material, its resistance (R) is determined by the formula R = ρ * (L/A), where ρ (rho) is the resistivity of the material, L is the length of the resistor, and A is the area of its cross-section.

According to the formula R = ρ * (L/A), the resistance is affected by the resistivity of the material, the length, and the area of cross-section. The current flowing through the resistor is a result of the applied voltage and the resistor’s resistance (as described by Ohm’s law, V=IR). Changing the voltage changes the current, but the resistance of the resistor itself remains constant (assuming constant temperature and material properties). Therefore, the current through the resistor does not affect its resistance; rather, the resistance affects the current for a given voltage.

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