61. A Distributor is designed on the basis of :
(A) current carrying capacity
(B) voltage drop
(C) power factor of the load
(D) frequency of supply
62. When a pipe electrode is used for earthing, the length of pipe should be atleast ________, while plate electrode is used, the length of the plate should be at least ____
(A) 2.5 m, 2.5 m
(B) 1.5 m, 2.5 m
(C) 2.5 m, 1.5 m
(D) 1.5 m, 1.5 m
63. The major drawback of primary cell is that :
(A) Chemical action is not reversible
(B) Chemical action is reversible
(C) The electrolyte used is very costly
(D) It is not portable
64. Which of the following will not prevent a self excited d.c. shunt generator from building up of its rated e.m.f. ?
(A) no residual magnetism
(B) wrong direction of rotation
(C) rated speed
(D) open field winding
65. A thyristor (SCR) is a :
(A) 3 layer, 3 terminal, 3 junction device
(B) 4 layer, 3 terminal, 3 junction device
(C) 4 layer, 3 terminal, 4 junction device
(D) 3 layer, 4 terminal, 3 junction device