Quiz sheet for three phase delta connected systems

To correctly connect three windings, A, A1; B, B1and C, C1 in delta, the wiring connections would be:

A) A1 to B, B1 to C and C1 to A

B) B1 to C1 to Al1

C) A to B to C 

D) A to B1, B1 to C and C to A1

ANSWER: A

In a delta connected system the angle between the line current and the phase current is:

A) 0°

B) 30°

C) 90°

D) 120°

ANSWER: B

The ratio of  the line voltage to the phase voltage in a delta connected system is:

A) 1:1

B) 1:1.414

C) \( \sqrt{3} \):1

D) 1:1.732

ANSWER: A

The resultant voltage around a closed delta connection is calculated from the:

A) phasor sum of the phase voltages

B) phasor difference of the phase voltages

C) algebraic difference of the phase voltages

D) numerical sum of the phase voltages

ANSWER: A

The line voltage of a delta connected system is approximately:

A) the same as the phase voltage

B) half the phase voltage

C) 1.73 times the phase voltage

D) 57.8% of the phase voltage

ANSWER: A

The available power from an open delta connected transformer compared to a delta connected transformer is: 

A) 57.7%

B) 33.3%

C) 66.7%

D) 50%

ANSWER: A

The resultant voltage around the closed loop of a delta connected transformer with one phase winding reversed is:

A) twice the phase voltage

B) equal to the phase voltage 

C) half the phase voltage 

D) zero

ANSWER: A

The ratio of line current to phase current in a delta connected system is: 

A) 1.73:1

B) 1:1

C) 1:1.73

D) 1.414:1

ANSWER: A

If a delta connected load has one supply line open circuited then there will be:

A) equal current in two phases 

B) zero current in one phase 

C) equal current in all phases 

D) zero current in all phases

ANSWER: A

The resultant voltage in a correctly closed delta system is equal to:

A) Zero

B) Phase voltage

C) Line voltage

D) 1.73 times phase voltage

ANSWER: A

Last modified: Monday, 31 May 2021, 9:09 PM