Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
18 Cards in this Set
- Front
- Back
|
What is D.C.? |
Direct Current ~ flows in one direction. E.g. a torch |
|
|
What is A.C.? |
Alternating Current ~ Repeatedly reverses it's direction of flow. E.g. mains electricity |
|
|
What is the peak potential difference of an a.c. supply? |
The maximum voltage measured from zero volts. |
|
|
What is the equation for the frequency of an a.c. supply? |
Frequency = 1 / time taken for 1 cycle |
|
|
What voltage does a typical power station generate? |
25000V |
|
|
Every mains circuit has what two types of wire? |
A live wire and a neutral wire |
|
|
What are sockets and plug cases made of and why? |
Stiff plastic because it is a good electrical insulator. |
|
|
What is a mains cable made up of? |
Two or three insulated copper wires surrounded by an outer layer of flexible plastic material. |
|
|
What colour is the live wire? |
Brown |
|
|
What colour is the neutral wire? |
Blue |
|
|
What colour is the neutral wire? |
Blue |
|
|
What colour is the earth wire? |
Green and yellow |
|
|
What is the earth wire connected to in a three pin plug? |
The longest pin in the plug |
|
|
What is the equation for electrical power? |
P = E / t Power = Energy transferred / time |
|
|
What is the equation linking current, power and resistance. |
P = I² * R |
|
|
What is an equation to remember how to work out the correct rating for a fuse? |
Electrical power (watts) ÷ Potential Difference (volts) |
|
|
What is the equation linking current, power supplies and potential difference. |
Power supplied = current * potential difference |
|
|
What is the equation for calculating charge. |
Charge flow = current * time Q = I * t |
