T2 questions 2
The RMS of a sinewave can be calculated by which of the following formula
peak x 0.707
the average of a sinewave can be calculated by which
peak x 0.637
the peak value of a sinewave can be calculated by which of the following
Average / 0.637
The peak value of a sinewave can be calculated by which of the following
average / 0.637
5. the peak to peak value of a sinewave can be calculated by which
peak x 2
6. the number of full cycles completed by a 50Hz AC supply in 1 minute is
3000
The average value of an ac waveform is calculated by the value of one half cycle of the sinewave only because
the average values of the positive and negative cycles equals 0 volts
which of the following cannot be displayed by an oscilloscope
RMS voltage value
the unit of measurement for the frequency of an alternating waveform is
Hertz
The property of an electrical circuit that opposes the change in current flow is
impedance
when a 50Hz AC supply of 230V is connected across the plates of a 400V capacitor that is connected in series with a lamp
The capacitor will charge and discharge in sequence with the frequency and the lamp will stay illuminated
The frequency of a 130V DC supply is
0Hz
The display on a digital volt-meter that is set at AC is there
Root mean squared value of the supply
The standard single phase supply voltage in Ireland is
230V
which of the following capacitors would have a higher reactance
125uf
the law that states 'If a coil is placed in the region of a changing magnetic flux, an EMF will be induced in the coil' is know as
faradays law
the SI unit of indcutance is
Henry
The CsA of the primary winding in a step down transformer that has a ratio of 10:1 is
smaller than the CSA of the secondary winding
Electrolytic capacitors
are polarised
which of the following does not affect capacitance value of a capacitor
plate thickness
Which of the following factors affect the magnitude of charge on a capacitor
voltage and capacitance