Q.61 Most electrical measuring instruments are constructed to read ___ of voltage and current being measured.
A. effective value
B. r.m.s value
C. virtual value
D. all of the above
Ans.: D
Q.62 The voltage and current ratings of electrical equipments are usually expressed in terms of____.
A. effective value
B. r.m.s value
C. virtual value
D. all of the above
Ans.: D
Q.63 In phasor diagrams the length of the phasors to represent the ___ of the sinusoidal quantities.
A. maximum value
B. average value
C. effective value
D. instantaneous value
Ans.: A
Q.64 It is common practice to draw the phasor diagram in terms of ____ rather than ___, in view of the greater importance of ____.
A. effective value, maximum value, maximum value
B. maximum value, maximum value, effective value
C. effective value, maximum value, effective value
D. maximum value, effective value, effective value
Ans.: C
Q.65 what is limitations of phasor diagram?
A. A phasor represents only one position of the wavefor
B. It does not give a complete description of a sinusoidal quantity
C. A phasor diagram is drawn to represent phasors at one frequency only
D. All of the above
Ans.: D
Q.66 Any phasor may drawn along convenient direction with respect to fixed phasor is known as___.
A. reference phasor
B. magnitude of phasor
C. angle of phasor
D. direction of phasor
Ans.: A
Q.67 when two alternating quantities have the same phase angle they are said to be___.
A. in same direction
B. in phase
C. out of phase
D. same magnitude
Ans.: B
Q.68 which of the following is true for in phase quantities?
A. they begin simultaneously and end simultaneously
B. they also reach their maximum values at the same time
C. they pass through zero at the same time
D. all of the above
Ans.: D
Q.69 The ____ are used to describe the relative position in time of two sinusoidal alternating quantities that are not in phase.
A. lead
B. lag
C. Both A and B
D. out of phase
Ans.: C
Q.70 An alternating quantity that ahead in time is called as __ and that one which is behind is called as __.
A. lags, lead
B. lead, leads
C. lead, lags
D. lags, out of phase
Ans.: C
Q.71 The equation of an alternating current is i= 42.42 sin 628t. what is the maximum value and rms value?
A. 42.42A, 30A
B. 30A, 42.42A
C. 30 A, 628A
D. 628A, 42.42A
Ans.: A
Q.72 A wire which carries simultaneously a direct current of 5A and a sinusoidal alternating current with a peak value of 5A. Find the rms value of a resultant current.
A. 61.2A
B. 612 A
C. 6.12 A
D. 0.162 A
Ans.: C
Q.73 _____ is defined as the rate of change of angle with respect to time.
A. The angular momentum
B. The angular velocity
C. Frequency
D. all of the above
Ans.: B
Q.74 the voltage measured from the baseline of an ac waveform to its maximum or peak level is known as__.
A. Amplitude
B. maximum value
C. Peak value
D. all of the above
Ans.: D
Q.75 Peak to peak values is most often used when measuring the amplitude on the _____.
A. cathode ray oscilloscope
B. cathode ray tube
C. in DC measuring instrument
D. all of the above
Ans.: B