Ques 11. Two waves of the same frequency have opposite phase when the phase angle between them is
360°
180°
90°
0°
Answer.2. 180°
Explanation:
If the phase difference is 180 degrees (π radians), then the two sine waves are said to be in anti-phase or Phase opposition i.e if one wave reaches its maximum value, then other will reach its minimum value.
Ques 12. The power consumed in a circuit element will be least when the phase difference between the current and voltage is
180″
90°
60°
0°
Answer.2. 90°
Explanation:
Power is given as
P = VIcosΦ
Hence power will be maximum when sinΦ = 90°
Pmax = VIsin90°
Pmax = VI
Ques 13. The r.m.s. value and the Average value is the same in the case of
Triangular wave
Sine wave
Square wave
Half-wave rectified sine wave
Answer.3. Square Wave
Explanation:
The R.M.S value of Square wave is given as
The Average value of square wave is given as
Hence in case of square wave, the R.M.S voltage and Average Voltage is equal to peak voltage
Ques 14. For the same peak value which of the following wave will ‘have the highest r.m.s. value ?
Square wave
Half-wave rectified sine wave
Triangular wave
Sine wave
Answer.1. Square Wave
Explanation:
In the square wave, the R.M.S value and average value are same.
But, in other kinds of waveforms (for example, sine, triangle, rectangle, etc), the average value is less than the RMS value.
Ques 15. For the same peak value, which of the following wave has the least mean value?
Half-wave rectifier sine wave
Triangular wave
Sine wave
Square wave
Answer.1. Half-wave rectifier sine wave
Explanation:
The average value of half-wave rectifier sine wave is 0.318 which is least as compared to triangular wave(0.5), sine wave (0.637) and square wave
Ques 16. For a sine wave with peak value Imax the r.m.s. value is
5 Imax
0.707Imax
9Imax
0.414Imax
Answer.2. 0.707Imax
Explanation:
Ques 17. Form Factor is the ratio of
Average value/r.m.s. value
Average value/peak value
R.M.S value/average value
R.M.S value/peak value
Answer.3. R.M.S value/average value
Explanation:
In electrical, the form factor of an alternating current waveform (signal) is the ratio of the RMS (root mean square) value to the average value (mathematical mean of absolute values of all points on the waveform).
Ques 18. Form factor for a sine wave is
1.414
0.707
1.11
0.637
Answer.3. 1.11
Explanation:
Form factor is the ratio of R.M.S value/Average value
R.M.S value of sine wave = 0.707
Average value of sine wave = 0.637
Therefore Form factor = 0.707/0.637
=1.109 ≅ 1.11
Ques 19. For a sine wave with peak value Vmax the average value is
0.637 Vmax
0.707 Vmax
0.434 Vmax
1.414Vmax
Answer.1. 0.637 Vmax
Explanation:
Ques 20. For a frequency of 200 Hz, the time period will be
