The flow of electical charge- the greater the rate of flow, the higher the current
1 of 20
What is current measured in?
amperes (A), amps using a ammeter
2 of 20
Word equation for charge flow?
charge flow= current x time
3 of 20
What is resistance?
The measure of how the component resists the flow of charge
4 of 20
What happens when there is a high resistance?
The more difficult it is for charge to flow and there is a lower current
5 of 20
What is resistance measured in?
Ohms
6 of 20
What is potential difference?
(also known as voltage) It tells us the difference in electrical potential from one point in a circuit to another
7 of 20
What happens when there is a bigger potential difference?
The greater the flow of charge through the component and the bigger the current
8 of 20
What is potential difference measured in?
Volts (V) using a voltmeter
9 of 20
Word equation for potential difference
Potential difference = current x resistance V=IR
10 of 20
Series circuit
There is the same current through each component. The total potential difference of the power supply is shared between the component. Adding resistors increases the total resistance
11 of 20
Parallel circuit
The potential difference across each component is the same. Adding resistors reduces the total resistance. The total current is the sum of currents through separate components and the total resistance of the two resistance is less than the resistanc
12 of 20
Word equation for power
power = potential difference x current OR power = (current). x resitance
13 of 20
What is dc?
direct current
14 of 20
What is ac?
alternating current
15 of 20
What is direct current?
It has a direct potential difference and is the type of current that is supplied by cells and batteries
16 of 20
What is alternating current?
It has an alternating potential difference and is the type of current used in main electricity
17 of 20
Word equation for energy transferred
power x time or charge flow x potential difference
18 of 20
What are step up transformers?
Increase the potential difference and reduce the current, therefore reduces the heat. Reducing the heating effect, reduces energy loss so makes the transmission more efficient
19 of 20
What is a step down transformer?
Reduce the potential difference from the transmission cables to a much lower value for domestic use so it is safe to use
Comments
No comments have yet been made