141. Transposition of conductors in transmission line system is done when
A. the conductors are not spaced equilaterally
B. the conductors are spaced equilaterally
C. a telephone line runs parallel to power line
D. none of these
142. The surge impedance of a transmission line differs from its characteristic impedance in that the surge impedance considers line
A. inductance to be zero
B. capacitance to be zero
C. resistance to be infinite
D. both A and B above
143. Relative to fair wheather, in humid weather corona occurs at
A. lower voltage
B. higher voltage
C. almost the same voltage
D. none of these
144. For the same power transmission, if the transmitted voltage increases by factor n, the size of the conductor gets multiplied by factor
A. 1/n2
B. n2
C. 1/n3
D. n3
145. The ground should not be smaller than
A. No. 6 copper
B. No. 8 copper
C. No. 10 copper
D. No. 12 copper
146. In a power transmission line, grounding is generally done at
A. the supply end
B. the receiving end
C. middle of the line
D. none of these
147. Earthing of power transmission line is necessary to provide protection against
A. overload
B. voltage fluctuation
C. electric shock
D. temperature rise of conductors
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