For the protection of power station buildings against direct strokes the requirements are___________?
(A) interception
(B) interception and conduction
(C) interception, conduction and dissipation
(D) interception, conduction, dissipation and reflection
(D) none of the above
Wave trap is used to trap waves of__________________?
(A) power frequencies
(B) higher frequencies entering generator or transformer units
(C) either of the above
(D) none of the above
Resistance grounding is used for voltage between_________________?
(A) 33kVto66kV
(B) HkVto33kV
(C) 3.3kVandllkV
(D) none of the above
Interruption of large currents by relay requires______________?
(A) arc suppressing blow out coils
(B) wide separation of the opened contacts
(C) high speed opening of contacts
(D) all of the above
The arc voltage produced in A.C. circuit breaker is always_____________?
(A) in phase with the arc current
(B) lagging the arc current by 90″
(C) leading the arc current by 90°
(D) none of the above
Overheating of relay contacts or contact born out is due to_______________?
(A) slow making and breaking of load circuit contacts
(B) foreign matter on the contact surface
(C) too low contact pressure
(D) all of the above
Shunt capacitance is neglected while considering______________?
(A) short transmission line
(B) medium transmission line
(C) long transmission line
(D) medium and long transmission lines
Ionization in circuit breaker is facilitated by___________?
(A) high temperature
(B) increase of mean free path
(C) increasing field strength
(D) all of the above
To reduce short circuit fault currents are used_____________?
(A) reactors
(B) resistors
(C) capacitors
(D) none of the above