# Scott & Zig-Zag Connection in Three Phase Transformers - MCQs with Answers

## Scott & Zig-Zag Connection in Three Phase Transformers - MCQs with Answers

Q1. Scott connection is used for the conversion of

a. Single phase to three phase
b. Three phase to single phase
c. Single phase to two phase
d. All of these

ANSWER: c. Single phase to two phase

Q2. In Scott connection, the voltage across the teaser leads the mains by

a. 30 degree
b. 60 degree
c. 90 degree
d. 120 degree

Q3. In a single phase, full wave bridge circuit and in three phase, delta full wave bridge circuit, the ripple voltage frequency is always

a. Twice the line frequency, six times the line frequency
b. Both will be twice the line frequency
c. Both will be six times the lines frequency
d. None of these

ANSWER: a. Twice the line frequency, six times the line frequency

Q4. Most familiar application of zig-zag transformer is as

a. Ground reference on an ungrounded system
b. Converting single phase to two phase
c. Reducing harmonics
d. All of these

ANSWER: a. Ground reference on an ungrounded system

Q5. In double delta transformation, a double delta refers to the case where there are two delta transformations in

a. Parallel
b. Series
c. Both series and parallel
d. Neither series nor parallel

Q6. A differential relay comparator used for the protection of three phase transformers has

a. One comparator
b. Two comparator
c. Three comparator
d. Six comparator