Transmission and distribution

[amp_mcq option1=”4.3 m” option2=”5.5 m” option3=”7.0 m” option4=”10.5 m” correct=”option1″]

Detailed SolutionThe minimum clearance between the ground and a 220 kV line is about

[amp_mcq option1=”crystallisation of the lead through vibration” option2=”chemical action on the lead when buried in the earth” option3=”mechanical damage” option4=”all of the above” correct=”option4″]

Detailed SolutionThe cause of damage to the lead sheath of a cable is

[amp_mcq option1=”20-30 ohms” option2=”70-80 ohms” option3=”100-200 ohms” option4=”500-1000 ohms” correct=”option3″]

Detailed SolutionFor an overhead line, the surge impedance is taken as

[amp_mcq option1=”Size of the conductor” option2=”Shape of the conductor” option3=”Surface condition of the conductor” option4=”All of the above” correct=”option4″]

Detailed SolutionThe corona is considerably affected by which of the following?

[amp_mcq option1=”Current flows through the half cross-section of the conductor” option2=”Portion of the conductor near the surface carries more current and core of the conductor carries less current” option3=”Portion of the conductor near the surface carries less current and core of the conductor carries more current” option4=”Any of the above” correct=”option2″]

Detailed SolutionOwing to skin effect

[amp_mcq option1=”31.25 percent of copper” option2=”33.3 percent of copper” option3=”distributor, a 3-wire distributor with same maximum voltage to earth uses only A. 31.25 percent of copper B. 33.3 percent of copper C. 66.7 percent of copper” option4=”125 percent of copper” correct=”option1″]

Detailed SolutionAs compared to a 2-wire D.C. distributor, a 3-wire distributor with same maximum voltage to earth uses only

[amp_mcq option1=”Increase of short-circuit current of the system” option2=”Availability of steady voltage at all loads at the line terminals” option3=”Possibility of better protection for the line due to possible use of higher terminal reactants” option4=”Improvement of power factor at times of moderate and heavy loads” correct=”option1″]

Detailed SolutionWhich of the following is the demerit of a ‘constant voltage transmission system’?

[amp_mcq option1=”Quartz” option2=”Kaolin” option3=”Felspar” option4=”Silica” correct=”option4″]

Detailed SolutionWhich of the following is not a constituent for making porcelain insulators?

[amp_mcq option1=”Ring bus-bar scheme” option2=”Single bus-bar scheme” option3=”Breaker and a half scheme” option4=”Main and transfer scheme” correct=”option1″]

Detailed SolutionWhich of the following bus-bar schemes has the lowest cost?

[amp_mcq option1=”Surge impedance of the line” option2=”Conductance of the line” option3=”Regulation of the line” option4=”None of the above” correct=”option1″]

Detailed SolutionThe square root of the ratio of line impedance and shunt admittance is called the