Quiz sheet for RL and RC circuits

The opposition to current in an AC circuit is termed

A) impedance

B) capacitance

C) inductance

D) resistance 

ANSWER: A

A practical inductor contains some resistance. Therefore, the angle between supply voltage and current for the total inductor is

A) less than 90 degrees

B) greater than 90 degrees

C) equal to zero

D) greater than 180 degrees

ANSWER: A

The direction of phasor rotation is

A) always anticlockwise

B) always clockwise

C) clockwise when the current lags the voltage

D) anticlockwise when the current leads the voltage

ANSWER: A

If A and B are two voltages of 300 and 400 volts operating at an angle of 90 degrees to each other the resultant voltage is:

A) 500 volts 

B) 100volts 

C) -100 volts 

D) -700 volts 

ANSWER: A

The cosine of the angle 90 degrees is equal to

A) 0

B) 1

C) 0.707

D) -0.707

ANSWER: A

When drawing the currents and voltage in a phasor diagram representing a three branch AC circuit, the reference phasor is the

A) supply voltage 

B) current in the  first branch 

C) current in any purely resistive branch 

D) supply current 

ANSWER: A

When representing AC quantities by phasors, the phasors are drawn to scale to represent

A) rms value

B) instantaneous values

C) maximum values

D) average values 

ANSWER: A

When drawing the phasor diagram for a series AC circuit containing containing resistance inductance and capacitance reference phasor is

A) supply current

B) supply voltage

C) capacitor voltage drop

D) inductor voltage drop

ANSWER: A

The resultant of two voltages, having the same angle of lag but different numerical values, can be determined by

A) numerical addition

B) numerical subtraction

C) phasor subtraction 

D) the addition of the numerical values and angles

ANSWER: A

A capacitor and resistor are connected in series to a 250volts 50 Hz supply. If the capacitor voltage drop is 150 volts, the resistor voltage drop would be

A) 200 volts 

B) 0 volts 

C) 100 volts 

D) 400 volts 

ANSWER: A


Last modified: Monday, 31 May 2021, 9:32 PM