Electricity

Question 1

What direction do electrons flow around a circuit

Answer 1

Electrons flow away from the negative terminal of a cell towards the positive terminal. In the opposite direction to the conventional current.

Question 2

State Ohms law

Answer 2

For a conductor at a constant temperature (constant resistance), the current through it is proportional to the potential difference across it.

V=IR

Question 3

Define resistivity

Answer 3

Resistivity is a property that describes the extent to which a material opposes the flow of electric current through it

Question 4

Thermistors are temperature sensors. As its temperature increases what happens to resistance?

Answer 4

As the thermistor gets hotter, its resistance decreases

Question 5

How can the resistivity of a material be lowered?

Answer 5

The resistivity of a material can be lowered by lowering its temperature

Question 6

How can the resistivity of a material be lowered?

Answer 6

The resistivity of a material can be lowered by lowering its temperature

Question 7

What is a superconductor

Answer 7

A material with no resistance below a critical temperature

Question 8

What is kirchhoff’s first law

Answer 8

At a junction in an electrical circuit, the sum of currents flowing into the junction is equal to the sum of currents flowing out of the junction.

Question 9

What is Kirchhoff’s first law

Answer 9

At a junction in an electrical circuit, the sum of currents flowing into the junction is equal to the sum of currents flowing out of the junction.

Question 10

What is Kirchhoff’s second law

Answer 10

The sum of the e.m.f’s in a closed circuit equals the sum of the potential differences.

Question 11

Define EMF

Answer 11

The amount of chemical energy converted to electrical energy per coulomb of charge (C) when passing through a power supply