Flashcards in Alternating currents Deck (10):

1

What is alternating current or voltage?

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- one that changes direction at time
- voltage acrtoss a resistance goes up and down in a regular pattern
- some of the time its positive and some of the time its negative

- some of the time its positive and some of the time its negative

2

What is an oscilliscope used for>?

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- display the voltage of an alternating current (and direct too)
- like fancy voltmeters
- vertical heigh of the trace at any point shows the input voltage at that point

3

What is the grid on the oscilliscope?

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- select how many volts per division you want on the y axis scale to represent the y-gain control dial

4

What is the pattern of an alternating current and a DC?

What happens if you turn time base off?>

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- gives a regularly repeating sinusodial waveform
- DC gives straigh line, always same voltage
- time base off - displayed as vertical line for ac, and dot for DC

5

What is peak voltage?

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- `V
_{0}
- ampltude

_{0}

6

What is peak-to-peak voltage?

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- distance between peak to trough

7

Peak voltage of ac = 2.0V

whyu will this not have a same power supply a 2V dc

what do you need to do to compare?

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- will be below 2 V most of the time
- won't have as high power output as 2 V dc supply
- need to take root mean squre (rms) voltage
- equation on data sheet
- same can be done for current

- equation on data sheet
- same can be done for current

8

How do you work of the rms power?

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- power
_{rms} = I_{rms }x V_{rms}

_{rms}= I_{rms }x V_{rms}
9

How is the freq on a oscilliscoep worked out

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- as long as time base setting is known
- 1 / T
- measuer distance between successive peaks along the time (horizontal) axis gives time period

10

What is the UK's mains electrical supply?