Electrical resistance is a property of a material that resists the flow of electric current through it.
How is resistance calculated using Ohm's Law?
Resistance is calculated using Ohm's Law as R = V/I, where R is resistance, V is voltage, and I is current.
What factors affect the resistance of a conductor?
The resistance of a conductor is affected by its length, cross-sectional area, material, and temperature.
Why does resistance increase with temperature in metallic conductors?
Resistance increases with temperature in metallic conductors because atomic vibrations increase, hindering the flow of electrons.
What is resistivity and how is it related to resistance?
Resistivity is a material-specific property that quantifies how strongly a material opposes the flow of electric current. It is related to resistance through the formula R = ρ(L/A).
What unit is used to measure resistance?
Resistance is measured in ohms, symbolized by the Greek letter Ω (omega).
What is the role of a resistor in an electrical circuit?
A resistor limits the flow of electric current in a circuit and is used to control the current to other components.
What happens to the resistance if the length of a wire is doubled?
If the length of a wire is doubled, its resistance also doubles, assuming the material and cross-sectional area remain constant.
What is a superconducting material?
A superconducting material is one that can conduct electricity without resistance below a certain temperature called the critical temperature.
Can resistance be negative?
In classical physics, resistance cannot be negative. Negative differential resistance can occur in certain electronic components due to specific interactions.
How does the cross-sectional area of a wire affect its resistance?
The resistance of a wire decreases as its cross-sectional area increases, as they are inversely proportional.
What type of material typically has low resistivity?
Metals generally have low resistivity, which makes them good conductors of electricity.
How is a multimeter used to measure resistance?
A multimeter is used to measure resistance by setting it to the resistance (Ω) mode and connecting its probes across the component.
What is a variable resistor and its use?
A variable resistor, or potentiometer, is a device where the resistance can be adjusted manually to control the current in a circuit.
Does resistance increase or decrease when the diameter of the wire is doubled?
The resistance decreases when the diameter of the wire is doubled, assuming the material and length remain constant.