a) Protect the insulation b) Increase the cable capacity c) Increase the rate of heat dissipation d) Protect the cable from mechanical stresses Ans: (a)
a) Sheath effects b) Skin and proximity effects c) Both (a) and (b) d) None of these Ans: (c)
a) Pole b) Manhole c) Feeder pillar d) All of these Ans: (b)
a) Loading cycles in service b) Extra potential difference c) Increased pressure d) All of these Ans: (a)
a) Uses different dielectrics b) Uses different intersheaths c) Is classified according to its capacitance d) None of these Ans: (a)
a) (frequency)2 b) Maximum voltage c) Power factor d) Corona loss Ans: (a)
a) Each case has its own lead sheath b) Screen is perforated and each core has separate lead sheath c) Each core is surrounded by a metallised and perforated paper which is kept at earth potential d) None of these Ans: (c)
a) Sheath may burst due to oil expansion b) Decreased viscosity at high temperature cause oil to drain off from the higher levels c) Due to unequal expansion the voids may be created d) All of these Ans: (d)
a) High dielectric strength b) High mechanical stresses bearing capacity c) High insulation resistance d) All of these Ans: (c)
a) 10° C b) 25° C c) 45° C d) 65° C Ans: (d)