155. Transmission lines are classified as short, medium and long depending on the
A. length of line
B. charging current or no load current
C. capacitance of line
D. both A and B above

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156. A series compensated transmission line has better
A. transient stability
B. steady state stability
C. short circuit capacity
D. reactive capacity

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157. Reactive power can be injected into a trans-mission line by using
A. series capacitors
B. shunt capacitors and reactors
C. synchronous capacitors
D. all of these

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158. The earthing switch is generally installed on
A. main board
B. isolator frame
C. circuit breaker frame
D. none of the above

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159. Surge impedance of a single circuit transmission line is 400L2. The surge impedance of a double circuit line of the same type will be
A. 200 W
B. 400 W
C. 800 W
D. 1200 W

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160. 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

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161. 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

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