Electrics 2 - Current and uses

Question 1

Electrical current flows from high (positive) charge to low (negative) charge. This is called _________ __________ and measured in _____.

Answer 1

Potential difference, measured in volts

Question 2

The greater the potential difference, the more _____________ force which causes the current flow.

Answer 2

Electromotive force

Question 3

A volt is a measure of _________ __________

Answer 3

potential difference

Question 4

Current is measured in ____ and is the measure of what?

Answer 4

Amps
amount of charge flowing per-second

Question 5

Ohms law is

Answer 5

V = I x R

Question 6

If you have 3 resistors wired in series and their values are
5Ω
10Ω
2Ω
what is the total resistance?

Answer 6

Add then together
17Ω

Question 7

When resistors are wired in parallel you add a ‘1/’ to each resistor.

5Ω
10Ω
2Ω
what is the total resistance?

Answer 7

(1/5) + (1/10) + (1/2) = (1/0.8)
1.25Ω

Question 8

Components will often change in temperature when they are resisting. In which direction?

Answer 8

Heat up

Question 9

Some components resist more when they are warm. What property do these have?

Answer 9

PTC
Positive thermal coefficient of resistance

Question 10

Some components resist LESS when they are warm. What property do these have?

Answer 10

NTC
Negative thermal coefficient of resistance

Question 11

Electrical power is the rate at which ______ is pushed through a circuit.

Answer 11

energy (joules)

Question 12

The unit of electrical power is the

Answer 12

watt

Question 13

A short circuit occurs when there is a large potential difference without enough resistance. What are the dangers?

Answer 13

Current will be high creating a severe risk of fire.