Quiz # 3 Resistance and Resistivity

What is the unit of electrical resistance?

• Ampere

• Ohm

• Joules

• Volt

This factor that affects electron flow depends on the thickness, length, resistivity or kind of a material used.

• Current

• Voltage

• Resistance

• Power

Which one is a poor conductor of electricity?

• Human body

• Dry Wood

• Sea water

• Earth

This device is used to measure the resistance of a circuit?

• Ammeter

• Voltmeter

• Ohmmeter

• Power meter

The amount of charge flowing through a cross-sectional area of a wire per unit of time is called:

• Voltage

• Power

• Resistance

• Work

A wire of length L and cross-sectional area A has a resistivity ρ. Which of the

following formulas can be used to calculate the resistance of the wire?

• R = 𝜌𝐿/𝐴

• R = 𝜌𝐴/𝐿

• R = 𝐿/𝜌𝐴

• R = 𝐴 /𝜌𝐿

The resistance of a conductor is directly proportional to its length

• True

• False

The cross-sectional area of a conductor is one factor that determines the conductor's resistance to current.

• True

• False

A longer wire has lesser resistance than a shorter wire. Current must travel farther through a longer wire, so there are more chances for it to collide with particles of matter

• True

• False

A cooler wire has less resistance than a warmer wire. Cooler particles have less kinetic energy, so they move more slowly.

• True

• False