In the case of an unsymmetrical alternating current the average value must always be taken over__________?

Related Mcqs:

1. The r.m.s. value of alternating current is given by steady (D.C.) current which when flowing through a given circuit for a given time produces__________?

   A. the more heat than produced by A.C. when flowing through the same circuit
   B. the same heat as produced by A.C. when flowing through the same circuit
   C. the less heat than produced by A.C. flowing through the same circuit
   D. none of the above

2. In each of the three coils of a three phase generator, an alternating voltage having an r.m.s. value of 220 V is induced. Which of the following values is indicated by the voltmeters ______?

   A. 220 V
   B. 220V3V
   C. 220/V3 V
   D. none of the above

3. What will be the phase angle between two alternating waves of equal frequency, when one wave attains maximum value the other is at zero value________ ?

   A. 0°
   B. 45°
   C. 90°
   D. 180°

4. The reactance offered by a capacitor to alternating current of frequency 50 Hz is 20 Q. If frequency is increased to 100 Hz, reactance becomes_______ohms?

   A. 2.5
   B. 5
   C. 10
   D. 15

5. The frequency of an alternating current is____________?

   A. the speed with which the alternator runs
   B. the number of cycles generated in one minute
   C. the number of waves passing through a point in one second
   D. the number of electrons passing through a point in one second

6. When an alternating current passes through an ohmic resistance the electrical power converted into heat is__________?

   A. apparent power
   B. true power
   C. reactive power
   D. none of the above

7. The square waveform of current has following relation between r.m.s. value and average value?

   A. r.m.s. value is equal to average value
   B. r.m.s. value of current is greater than average value
   C. r.m.s. value of current is less than average value
   D. none of the above

8. The peak value of a sine wave is 200 V. Its average value is___________?

   A. 127.4 V
   B. 141.4 V
   C. 282.8 V
   D. 200V

   Updated by: Ihtisham Ul Haq

9. For a sine wave with peak value Emax _______ 8.30. the average value is?

   A. 0.636 Emax
   B. 0.707 Emax
   C. 0.434 EWc
   D. lAUEmax

10. The r.m.s. value and mean value is the same in the case of___________?

    A. triangular wave
    B. sine wave
    C. square wave
    D. half wave rectified sine wave