What law is used to calculate the resistance, voltage across, or current through an electric device?

• Kirchhoff's law

• Faraday's law

• Ohm's law

• Joule's law

Answer explanation

Ohm's law is used to calculate the resistance, voltage across, or current through an electric device. It states that the current flowing through a conductor is directly proportional to the voltage applied and inversely proportional to the resistance of the conductor.

Which term describes the opposition that conductors present to current?

• Conductance

• Resistance

• Capacitance

• Inductance

Answer explanation

Resistance is the term that describes the opposition that conductors present to current. It is a measure of how much a material resists the flow of electric current.

What must be known to calculate the resistance of a material given its length, cross-sectional area, and resistivity?

• Ohm's law

• The American Wire Gauge table

• The voltage-current characteristic

• The color code

Answer explanation

To calculate resistance, knowledge of Ohm's law is required, which relates resistance, voltage, and current.

What can you use to calculate the resistance of a length of wire?

• The color code

• The American Wire Gauge table

• A potentiometer

• A thermistor

Answer explanation

The resistance of a length of wire can be calculated using the American Wire Gauge table.

What is the term for the specific resistance of a material?

• Conductivity

• Resistivity

• Reactance

• Impedance

Answer explanation

The term for the specific resistance of a material is resistivity. It represents the material's ability to resist the flow of electric current.

Who is the ohm, the unit of resistance, named after?

• Isaac Newton

• Georg Simon Ohm

• James Watt

• Alessandro Volta

Answer explanation

The ohm, the unit of resistance, is named after Georg Simon Ohm, who formulated Ohm's law relating current, voltage, and resistance.

What is the relationship between voltage (E), current (I), and resistance (R) according to Ohm's Law?

• E = IR

• E = I/R

• E = R/I

• I = ER

Answer explanation

According to Ohm's Law, the relationship between voltage (E), current (I), and resistance (R) is given by E = IR. This equation states that the voltage across a conductor is equal to the product of the current flowing through it and the resistance of the conductor.

What does the letter symbol 'R' stand for in the context of Ohm's Law?

• Ratio

• Reactance

• Resistance

• Radiance

Answer explanation

The letter symbol 'R' in Ohm's Law stands for Resistance, which is the measure of opposition to the flow of electric current.

What is the SI unit of electric resistance?

• Ampere

• Volt

• Ohm

• Watt

Answer explanation

The SI unit of electric resistance is Ohm. It is a measure of how much an object resists the flow of electric current.

What does one ohm equal?