Understanding Resistance and Resistivity

Which of the following factors does NOT affect the resistance of a conductor?

• Cross-sectional area

• Color of the conductor

• Length of the conductor

• Material of the conductor

What happens to the resistance of a wire if its length is doubled?

• The resistance is quadrupled

• The resistance remains the same

• The resistance is doubled

• The resistance is halved

How is resistivity defined in terms of its units?

• Ohms per square meter

• Meters per ohm

• Ohm-meters

• Ohms per meter

Which material is likely to have the lowest resistivity?

• Aluminum

• Iron

• Silver

• Copper

What is the relationship between voltage and current in an ohmic resistor?

• Voltage is independent of current

• Voltage is exponentially related to current

• Voltage is inversely proportional to current

• Voltage is directly proportional to current

Which of the following is a characteristic of a non-ohmic resistor?

• Linear relationship between voltage and current

• Constant resistance

• Resistance changes with temperature

• Resistance is independent of voltage

If a resistor has a resistance of 5 ohms and a current of 2 amps flows through it, what is the voltage across it?

• 1 volt

• 10 volts

• 5 volts

• 2.5 volts

What is the resistivity of a material if a wire of that material has a resistance of 3 ohms, a length of 75 meters, and a cross-sectional area of 2.4 mm²?

• 1.2 x 10^-8 ohm-m

• 3.2 x 10^-8 ohm-m

• 7.2 x 10^-8 ohm-m

• 9.6 x 10^-8 ohm-m

Which of the following statements is true about ohmic resistors?

• They have a non-linear voltage-current relationship

• Their resistance changes with voltage

• They follow Ohm's Law

• They are always made of metal

In a graph of voltage versus current, what does a steeper slope indicate about the resistor?

• Variable resistance

• Constant resistance

• Lower resistance

• Higher resistance