Power System MCQs | Object Questions and Answers

29. Transmission line are classified as short, medium and long depending on the

30. Corona is observed on

A. a.c. transmission lines only

B. d.c. transmission lines only

C. both a.c. and d.c. transmission lines

D. none of these

31. An advantage of corona on transmission lines is that

A. it minimizes power loss

B. it reflects electrical surges

C. it works as a surge modifier during overloads

D. none of these

32. As the moisture content in the air increases, the disruptive critical voltage

A. increases

B. decreases

C. remain constant

D. may increase or decrease

33. Inductance in henries/metre of a single phase two parallel wire transmission line having conductor radius r and spacing D between conductors is equal to

34. For torque angle 8, the condition for maximum power transmission

35. As per Indian Standards, the cross-sectional area of the neutral wire in a 3-phase 4 wire system is

A. twice that of a phase conductor

B. equal to that of a phase conductor

C. half that of a phase conductor

D. one-fourth that of a phase conductor