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Flashcards in Mains Electricity Deck (14)
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1
Q

What is the approximate voltage of the UK mains electricity supply?

A

230v

2
Q

What type of current is mains?

A

Alternating

3
Q

What is alternating current?

A

Current that is constantly changing direction

4
Q

What is the frequency of the AC mains supply?

A

50Hz

5
Q

What type of current do cells and batteries supply?

A

Direct current

6
Q

What is direct current?

A

Current that always flows in the same direction

7
Q

What is a CRO?

A

Similar to a voltmeter

If you plug an AC supply into an oscilloscope you get a trace showing how voltage changes with time (sometimes positive, sometimes negative)

8
Q

What happens if you plug a DC into an oscilloscope?

A

You get a straight line

9
Q

What does the vertical height of an AC trace show?

A

Input voltage at that point

10
Q

By measuring the height of the trace what can you find?

A

The potential difference of the AC supply

11
Q

For DC what is the voltage?

A

The distance from the straight line trace to the centre

12
Q

What does the Gain dial control?

A

How many bolts each centimetre division represents on the vertical axis

13
Q

What does the timebase dial control?

A

How many milliseconds each divisons represents on the horizontal axis

14
Q

How do you work out frequency?

A

1/ time period