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135 lines
1.7 KiB
Plaintext
135 lines
1.7 KiB
Plaintext
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% FILENAME = N8.TXT
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% Alternating Current
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% Release version 2, January 2000
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%Question: 1
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#8.1 An 'alternating current' is so called because:
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it reverses direction periodically
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it travels through a circuit using alternate paths
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its direction of travel is uncertain
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its direction of travel can be altered by a switch
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% ans 1
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%Question: 2
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#8.2 The time for one cycle of a 100 Hz signal is:
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1 second
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0.01 second
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0.0001 second
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10 seconds
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% ans 2
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%Question: 3
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#8.3 A 50 hertz current in a wire means that:
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a potential difference of 50 volts exists across the wire
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the current flowing in the wire is 50 amperes
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the power dissipated in the wire is 50 watts
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a cycle is completed 50 times in each second
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% ans 4
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%Question: 4
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#8.4 The current in an AC circuit completes a cycle in 0.1 second. So the frequency is:
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1 Hz
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10 Hz
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100 Hz
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1000 Hz
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% ans 2
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%Question: 5
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#8.5 An impure signal is found to have 2 kHz and 4 kHz components. This 4 kHz signal is:
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a fundamental of the 2 kHz signal
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a sub-harmonic of 2 kHz
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the DC component of the main signal
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a harmonic of the 2 kHz signal
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% ans 4
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%Question: 6
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#8.6 The correct name for the equivalent of 'one cycle per second' is one:
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henry
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volt
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hertz
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coulomb
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% ans 3
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%Question: 7
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#8.7 One megahertz is equal to:
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0.0001 Hz
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100 kHz
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1000 kHz
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10 Hz
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% ans 3
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%Question: 8
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#8.8 One GHz is equal to:
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1000 kHz
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10 MHz
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100 MHz
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1000 MHz
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% ans 4
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%Question: 9
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#8.9 The 'rms value' of a sine-wave signal is:
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half the peak voltage
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1.414 times the peak voltage
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the peak-to-peak voltage
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0.707 times the peak voltage
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% ans 4
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%Question: 10
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#8.10 A sine-wave alternating current of 10 ampere peak has an rms value of:
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5 amp
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7.07 amp
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14.14 amp
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20 amp
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% ans 2
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