Electronics - Electric Current (Module 12)

Question 1

Define charge carriers

Answer 1

These are charged particles that move through a substance when a pd is applied across it

Question 2

Define potential difference

Answer 2

This is defined as the work done (or energy transfer) per unit charge ( V = W/Q )

Question 3

Define emf of a source of electricity

Answer 3

This is the electrical energy produced per unit charge passing through the source

Question 4

Define resistance of a component

Answer 4

This is the pd across the component / the current passing through it

Question 5

Define Ohm’s Law

Answer 5

This states that the pd across a metallic conductor is proportional to the current through it, provided the physical conditions do not change

Question 6

Define resistivity

Answer 6

This is the resistance per unit length times the area of the cross section

Question 7

What is a superconductor?

Answer 7

It is a wire or a device made of material that has zero resistivity at and below a critical temperature that depends on the material.

Question 8

What is a light dependent resistor (LDR)?

Answer 8

This is a resistor which is designed to have a resistance that change with light intensity