AC Fundamentals

#1. 1

120*

90*

60*

180*

#2. 2

1.57

3.14

1.11

1.414

#3. 3

lags

leads

out of phase

in phase

#4. 4

time constant

resonance

amplitude

time period

#5. 5

VI Cos$

VI

VI Sin $

VIR

#6. Form factor is the ratio of….?

rms value / average value

average value / rms value

average value x rms value

instantaneous value x rms value

#7. The power factor of the inductive loading is….?

lagging

zero

unity

leading

#8. Impedance at series resonance circuit is….?

maximum

average

none of the above

minimum

#9. Power factor is defined as….?

kW/kVA

kW/kVR

kVAR/kVA

kVA/kW

#10. In a AC series circuits Q factor is….?

1/cos$

1/sin$

sin$

cos$

#11. Power factor of R-C series circuit is…..?

1

greater than 1

between 0 and 1

0

#12. Capacitive reactance is……?

independent of frequency

inversely proportional to frequency

directly proportional to frequency

directly proportional to capacitance

#13. The ratio of Z/R is…..?

form factor

power factor

reciprocal of power factor

reciprocal of form factor

#14. Admittance is the reciprocal of….?

reactance

susceptance

impedence

resistance

#15. The power factor of ordinary electric bulb is…?

one

zero

slightly less than one

slightly more than one

#16. Unit of inductive reactance is….?

hentry

weber

milli hentry

ohm

#17. Peak factor of a sinusoidal wave form is….?

1.11

1.41

1.21

1

#18. The rms value of a sine wave is 100A. Its peak value is…?

160 A

200 A

141 A

100 A

#19. The power factor of an AC circuit is equal to…..?

one

sine of the phase angle

cosine of the phase angle

unity for a resistive circuit

#20. Unit of reactive power is….?

ohm

VA

VAR

watt

#21. With in the increase in applied frequency, the dielectric loss will be….?

same

decrease

increase

one half

#22. With in the increase in applied frequency, the dielectric loss will be….?

one half

increase

same

decrease

#23. Q factor of a series R-L-C circuit possessing resonant frequency of 10 Hz and band width of 5 Hz is…?

2

4

5.5

2.5

#24. Power factor of an inductive circuit is usually improved by adding a capacitor to it in….?

series

either in series or parallel

parallel

#25. Form factor of a full rectified sine wave is…?

1.571

1.11

1

1.41

#26. Form factor of a full rectified sine wave is…?

1.11

1

1.571

1.41

rms / average = (Vm/2)/(Vm/pi) = 1.571

#27. An alternating current is given by i=14.14sin377t. find its rms value of current?

14.14 A

10 A

24 A

15 A

14.14/1.4 = 10A

#28. The ratio of maximum value to the rms value of an alternating quantity is called….?

form factor

peak factor

mean value

average value

#29. A seris RL circuit has a resistance of 30 ohms and an inductance of 40 ohms. The impedence is….?

50 ohms

70 ohms

40 ohms

90 ohms

Root of 900 1600 = 50

#30. The unit of capacitance is….?

watt

farad

ohm

hentry

#31. Two capacitors of 5 micro farad each are connected in series. the total capacitance is….?

8 mF

10 mF

16 mF

4 mF

8/2=4

#32. Capacitance is not affected by…?

plate area

dielectric material

distance between plates

frequency

#33. Two capacitors of 10 micro farad each are connected in parallel. the total capacitance is….?

100 mF

10 mF

5 mF

20 mF

#34. The capacitors opposition to alternating current is called…?

capacitance

capacitive reactance

resistance

impedence

#35. In a capacitive AC circuit is the…..?

current is inphase with voltage

current leads voltage

none of the above

current laggs voltage

#36. Which condition is called as resonance RLC circuit?

XL< XC

XL= XC

XL > XC

#37. The line voltage in three phase delta connection is….?

same as the phase voltage

Twice as phase voltage

none of these

Thrice as phase voltage

#38. The line voltage in three phase delta connection is….?

same as the phase current

none of these

Thrice as phase current

Twice as phase current

#39. Potential inside a hollow sphere charged with a voltage V is….?

0

V

2V

V/2

#40. The reciprocal of impedance is…?

susceptance

resistance

admittance

conductance

#41. Phase sequence is the order of attaining?

RMS value

Maximum value

Average value

None of the above

#42. In a R.L.C series resonant circuit….?

R=XL

XL>XC

R=XC

R=Z

#43. Two possible phase sequences are….?

RBY,YRB

BRY,RYB

RYB,YBR

RYB,RBY

#44. In a RLC resonant circuit magnification is…..?

WL/R

WLC

WL

Z

#45. Three phase inter connection used in 3 phase 4 wire distribution system is…..?

delta

delta delta

star star

star

AC Fundamentals

Results

#1. 1

#2. 2

#3. 3

#4. 4

#5. 5

#6. Form factor is the ratio of….?

#7. The power factor of the inductive loading is….?

#8. Impedance at series resonance circuit is….?

#9. Power factor is defined as….?

#10. In a AC series circuits Q factor is….?

#11. Power factor of R-C series circuit is…..?

#12. Capacitive reactance is……?

#13. The ratio of Z/R is…..?

#14. Admittance is the reciprocal of….?

#15. The power factor of ordinary electric bulb is…?

#16. Unit of inductive reactance is….?

#17. Peak factor of a sinusoidal wave form is….?

#18. The rms value of a sine wave is 100A. Its peak value is…?

#19. The power factor of an AC circuit is equal to…..?

#20. Unit of reactive power is….?

#21. With in the increase in applied frequency, the dielectric loss will be….?

#22. With in the increase in applied frequency, the dielectric loss will be….?

#23. Q factor of a series R-L-C circuit possessing resonant frequency of 10 Hz and band width of 5 Hz is…?

#24. Power factor of an inductive circuit is usually improved by adding a capacitor to it in….?

#25. Form factor of a full rectified sine wave is…?

#26. Form factor of a full rectified sine wave is…?

#27. An alternating current is given by i=14.14sin377t. find its rms value of current?

#28. The ratio of maximum value to the rms value of an alternating quantity is called….?

#29. A seris RL circuit has a resistance of 30 ohms and an inductance of 40 ohms. The impedence is….?

#30. The unit of capacitance is….?

#31. Two capacitors of 5 micro farad each are connected in series. the total capacitance is….?

#32. Capacitance is not affected by…?

#33. Two capacitors of 10 micro farad each are connected in parallel. the total capacitance is….?

#34. The capacitors opposition to alternating current is called…?

#35. In a capacitive AC circuit is the…..?

#36. Which condition is called as resonance RLC circuit?

#37. The line voltage in three phase delta connection is….?

#38. The line voltage in three phase delta connection is….?

#39. Potential inside a hollow sphere charged with a voltage V is….?

#40. The reciprocal of impedance is…?

#41. Phase sequence is the order of attaining?

#42. In a R.L.C series resonant circuit….?

#43. Two possible phase sequences are….?

#44. In a RLC resonant circuit magnification is…..?

#45. Three phase inter connection used in 3 phase 4 wire distribution system is…..?

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