Top 150+ Solved DC Generators MCQ Questions Answer
Q. The intersheaths in the cables are used to
a. minimize the stress
b. avoid the requirement of good insulation
c. provide proper stress distribution
d. none of the above
Q. The electrostatic stress in underground cables is
a. same at the conductor and the sheath
b. minimum at the conductor and maximum at the sheath
c. maximum at the conductor and minimum at the sheath
d. zero at the conductor as well as on the sheath
Q. The breakdown of insulation of the cable can be avoided economically by the use of
a. inter-sheaths
b. insulating materials with different dielectric constants
c. both (a) and (b)
d. none of the above
Q. The insulation of the cable decreases with
a. the increase in length of the insulation
b. the decrease in the length of the insulation
c. either (a) or (b)
d. none of the above
Q. A cable carrying alternating current has
a. hysteresis losses only
b. hysteresis and leakage losses only
c. hysteresis, leakage and copper losses only
d. hysteresis, leakage, copper and friction losses
Q. In a cable the voltage stress is maximum at
a. sheath
b. insulator
c. surface of the conductor
d. core of the conductor
Q. Capacitance grading of cable implies
a. use of dielectrics of different permeabilities
b. grading according to capacitance of cables per km length
c. cables using single dielectric in different concentrations
d. capacitance required to be introduced at different lengths to counter the effect of inductance
Q. Underground cables are laid at sufficient depth
a. to minimise temperature stresses
b. to avoid being unearthed easily due to removal of soil
c. to minimise the effect of shocks and vibrations due to gassing vehicles, et
d. for all of the above reasons
Q. The advantage of cables over overhead transmission lines is
a. easy maintenance
b. low cost
c. can be used in congested areas
d. can be used in high voltage circuits
Q. The thickness of metallic shielding on cables is usually
a. 0.04 mm
b. 0.2 to 0.4 mm
c. 3 to 5 mm
d. 40 to 60 mm
Q. Cables for 220 kV lines are invariably
a. mica insulated
b. paper insulated
c. compressed oil or compressed gas insulated
d. rubber insulated
Q. Is a cable is to be designed for use on 1000 kV, which insulation would you prefer ?
a. Polyvinyle chloride
b. Vulcanised rubber
c. Impregnated paper
d. Compressed SFe gas
Q. If a power cable and a communication cable are to run parallel the minimum distancebetween the two, to avoid interference, should be
a. 2 cm
b. 10 cm
c. 50 cm
d. 400 cm
Q. Copper as conductor for cables is used as
a. annealed
b. hardened and tempered
c. hard drawn
d. alloy with chromium
Q. The insulating material should have
a. low permittivity
b. high resistivity
c. high dielectric strength
d. all of the above