Chap 14: Current of Electricity

Question 1

Electric current

Answer 1

Rate of flow of positive charges.

Example sentence: The electric current in the circuit is measured in amperes.

Question 2

Potential difference between two points in a circuit

Answer 2

Amount of energy per unit charge converted from electrical energy to other forms of energy when the charge passes between the two points.

Example sentence: The potential difference across the resistor is 12 volts.

Question 3

Electromotive force (e.m.f.) of a source

Answer 3

The amount of energy converted per unit charge from other forms to electrical energy when the source drives a charge round a complete circuit.

Example sentence: The e.m.f. of the battery is 1.5 volts.

Question 4

Resistance (of a component)

Answer 4

Ratio of the potential difference across the component to the current flowing through it.

Example sentence: The resistance of the resistor is 10 ohms.

Question 5

Ohm

Answer 5

One ohm is defined as the resistance of a conductor when the current of ONE AMPERE passes through it when the potential difference is ONE VOLT

Question 6

Resistivity

Answer 6

It is the constant of proportionality for the relationship between a conductor’s resistance, length and cross sectional area