The tendency for a material to oppose the flow of electrons, measured in ohms, is known as?

The tendency for a material to oppose the flow of electrons, measured in ohms, is known as?

• A. Capacitance
• B. Inductance
• C. Impedance
• D. Resistance

Answer: (D)

Opposition to the flow of electric current in a conductor is called resistance. It tells you how much voltage is needed to push a certain current through the material, via Ohm’s law V = IR, with the unit of resistance being the ohm. Resistance depends on the material’s properties (resistivity), its shape and size (length and cross-sectional area), and temperature. In AC circuits, you also hear about impedance, which is the total opposition to current that includes both resistance and reactive effects from inductors and capacitors; impedance is measured in ohms too but is a broader concept and generally has both magnitude and phase. Capacitance stores charge, not oppose current, and inductance relates to energy storage in a magnetic field. The description given points to resistance.

Opposition to the flow of electric current in a conductor is called resistance. It tells you how much voltage is needed to push a certain current through the material, via Ohm’s law V = IR, with the unit of resistance being the ohm. Resistance depends on the material’s properties (resistivity), its shape and size (length and cross-sectional area), and temperature.

In AC circuits, you also hear about impedance, which is the total opposition to current that includes both resistance and reactive effects from inductors and capacitors; impedance is measured in ohms too but is a broader concept and generally has both magnitude and phase. Capacitance stores charge, not oppose current, and inductance relates to energy storage in a magnetic field. The description given points to resistance.