Current and circuits

Question 1

Electromotive force

Answer 1

equal to the terminal potential difference when no current flows (V)
- the amount of energy provided by the battery to each coulumb of charge (Q) passing through

Question 2

Direct current (I)

Answer 2

A flow of charge carriers in one direction only

Question 3

Electrical potential difference (V)

Answer 3

The work done per unit charge to move a positive charge between two points in a circuit.

Question 4

Electric resistance

Answer 4

A measure of how much a component resists the flow of electric current.

Question 5

Resistivity

Answer 5

A material property that quantifies how strongly a material opposes the flow of electric current.

Question 6

Ohm’s law

Answer 6

The current through a conductor is directly proportional to the voltage across it, provided temperature is constant.

Question 7

Ohmic vs. Non-ohmic conductors

Answer 7

Ohmic conductors follow Ohm’s Law (linear V-I
relationship), non-ohmic conductors do not (e.g., filament lamps).

Question 8

Conductors and insulators (mobility of charge carriers)

Answer 8

Conductors have free charge carriers that move easily; insulators do not allow free movement of charge.

Question 9

Cells and emf

Answer 9

A cell provides electromotive force (emf), the energy per unit charge supplied to the circuit.

Question 10

Chemical and solar cells

Answer 10

Devices that convert chemical or solar energy into electrical energy.

Question 11

Circuit diagrams

Answer 11

Graphical representations showing the arrangement and connections of components in an electric circuit.