If the resistivity of a material is halved, what happens to the resistance of a
Practice Questions
Q1
If the resistivity of a material is halved, what happens to the resistance of a wire of fixed length and cross-sectional area?
Halved
Doubled
Remains the same
Quadrupled
Questions & Step-by-Step Solutions
If the resistivity of a material is halved, what happens to the resistance of a wire of fixed length and cross-sectional area?
Correct Answer: Resistance bhi half ho jayegi.
Step 1: Understand that resistance (R) is a property of a material that depends on its resistivity (ρ), length (L), and cross-sectional area (A). The formula is R = ρ * (L / A).
Step 2: Identify that resistivity (ρ) is a measure of how strongly a material opposes the flow of electric current.
Step 3: Note that if the resistivity is halved, it means the new resistivity (ρ') is ρ/2.
Step 4: Substitute the new resistivity into the resistance formula: R' = (ρ/2) * (L / A).
Step 5: Simplify the equation: R' = (1/2) * (ρ * (L / A)) = (1/2) * R.
Step 6: Conclude that if the resistivity is halved, the resistance of the wire is also halved.
Ohm's Law – Resistance is directly proportional to resistivity, length, and inversely proportional to cross-sectional area.
Resistivity – Resistivity is a material property that affects the resistance of a wire.