In a -connected source driving a -connected load, the

load voltage and line voltage are one-third the source voltage for a given phase

load voltage and line voltage are two-thirds the source voltage for a given phase

load voltage and line voltage cancel for a given phase

load voltage, line voltage, and source phase voltage are all equal for a given phase

Compare the total copper cross sections in terms of current-carrying capacity for a single-phase and a three-phase 120 V system with effective load resistance of 15 .

single-phase 8 A; three-phase 4 A

single-phase 32 A; three-phase 16 A

single-phase 16 A; three-phase 8 A

single-phase 8 A; three-phase 4 A

single-phase 16 A; three-phase 0 A

In a Y-connected source feeding a -connected load,

each phase of the load has a voltage across it equal to

each phase of the load has one-third of the full line voltage across it

each phase of the load has two-thirds of the full line voltage across it

each phase of the load has the full line voltage across it

each phase of the load has a voltage across it equal to

In a -connected source feeding a Y-connected load,

each phase voltage equals the corresponding load voltage

each phase voltage equals the difference of the corresponding load voltages

each phase voltage equals the corresponding load voltage

each phase voltage is one-third the corresponding load voltage

each phase voltage is 60° out of phase with the corresponding load voltage

19 + Mcqs in Three-Phase Systems in Power Applications in Electrical Engineering Page 1 McqOptions

1.	In a -connected source driving a -connected load, the
A.	load voltage and line voltage are one-third the source voltage for a given phase
B.	load voltage and line voltage are two-thirds the source voltage for a given phase
C.	load voltage and line voltage cancel for a given phase
D.	load voltage, line voltage, and source phase voltage are all equal for a given phase
Answer» E.

Discussion

2.	In a -connected generator, there is a 120° difference between each line current and the nearest phase current.
A.	True
B.	False
Answer» C.

Discussion

3.	A balanced load is one in which all the impedances are equal.
A.	True
B.	False
Answer» B. False

Discussion

4.	The term applies to a type of three-phase ac generator.
A.	True
B.	False
Answer» B. False

Discussion

5.	A simple two-phase generator consists of two conductive loops separated by 90°, rotating in a magnetic field.
A.	True
B.	False
Answer» B. False

Discussion

6.	An alternator is an electromechanical ac generator.
A.	True
B.	False
Answer» C.

Discussion

7.	Power is measured in a three-phase load by using an ammeter.
A.	True
B.	False
Answer» C.

Discussion

8.	Polyphase is characterized by two or more sinusoidal voltages, each having a different phase angle.
A.	True
B.	False
Answer» B. False

Discussion

9.	In a Y-connected generator, there is a 120° difference between each line voltage and the nearest phase voltage.
A.	True
B.	False
Answer» C.

Discussion

10.	A simple three-phase generator consists of three conductive loops separated by 120°.
A.	True
B.	False
Answer» B. False

Discussion

11.	If in a Y-connected ac generator, each phase voltage has a magnitude of 90 V, what is the magnitude of each line voltage?
A.	0 V
B.	90 V
C.	156 V
D.	180 V
Answer» D. 180 V

Discussion

12.	A three-phase generator is connected to three 90 load resistors. Each coil generates 120 V ac. A common neutral line exists. How much current flows through the common neutral line?
A.	0 A
B.	1.33 A
C.	3.99 A
D.	2.66 A
Answer» B. 1.33 A

Discussion

13.	Compare the total copper cross sections in terms of current-carrying capacity for a single-phase and a three-phase 120 V system with effective load resistance of 15 .
A.	single-phase 32 A; three-phase 16 A
B.	single-phase 16 A; three-phase 8 A
C.	single-phase 8 A; three-phase 4 A
D.	single-phase 16 A; three-phase 0 A
Answer» C. single-phase 8 A; three-phase 4 A

Discussion

14.	In a Y-connected source feeding a -connected load,
A.	each phase of the load has one-third of the full line voltage across it
B.	each phase of the load has two-thirds of the full line voltage across it
C.	each phase of the load has the full line voltage across it
D.	each phase of the load has a voltage across it equal to
Answer» D. each phase of the load has a voltage across it equal to

Discussion

15.	The stator is the rotating assembly in a generator or motor.
A.	True
B.	False
Answer» C.

Discussion

16.	A two-phase generator is connected to two 90 load resistors. Each coil generates 120 V ac. A common neutral line exists. How much current flows through the common neutral line?
A.	1.33 A
B.	1.88 A
C.	2.66 A
D.	1.77 A
Answer» E.

Discussion

17.	A single-phase sinusoidal voltage of 120 V is connected to a 90 load. Current in the circuit is
A.	13.3 mA
B.	133 mA
C.	1.33 A
D.	6.2 A
Answer» D. 6.2 A

Discussion

18.	In a -connected generator, all of the phase voltages are
A.	zero
B.	equal in magnitude
C.	one-third of total
D.	one-sixth of total
Answer» C. one-third of total

Discussion

19.	In a -connected source feeding a Y-connected load,
A.	each phase voltage equals the difference of the corresponding load voltages
B.	each phase voltage equals the corresponding load voltage
C.	each phase voltage is one-third the corresponding load voltage
D.	each phase voltage is 60° out of phase with the corresponding load voltage
Answer» B. each phase voltage equals the corresponding load voltage

Discussion

Explore topic-wise MCQs in Electrical Engineering.

In a -connected source driving a -connected load, the

In a -connected generator, there is a 120° difference between each line current and the nearest phase current.

A balanced load is one in which all the impedances are equal.

The term applies to a type of three-phase ac generator.

A simple two-phase generator consists of two conductive loops separated by 90°, rotating in a magnetic field.

An alternator is an electromechanical ac generator.

Power is measured in a three-phase load by using an ammeter.

Polyphase is characterized by two or more sinusoidal voltages, each having a different phase angle.

In a Y-connected generator, there is a 120° difference between each line voltage and the nearest phase voltage.

A simple three-phase generator consists of three conductive loops separated by 120°.

If in a Y-connected ac generator, each phase voltage has a magnitude of 90 V, what is the magnitude of each line voltage?

A three-phase generator is connected to three 90 load resistors. Each coil generates 120 V ac. A common neutral line exists. How much current flows through the common neutral line?

Compare the total copper cross sections in terms of current-carrying capacity for a single-phase and a three-phase 120 V system with effective load resistance of 15 .

In a Y-connected source feeding a -connected load,

The stator is the rotating assembly in a generator or motor.

A two-phase generator is connected to two 90 load resistors. Each coil generates 120 V ac. A common neutral line exists. How much current flows through the common neutral line?

A single-phase sinusoidal voltage of 120 V is connected to a 90 load. Current in the circuit is

In a -connected generator, all of the phase voltages are

In a -connected source feeding a Y-connected load,