An impedance relay can be used for
Correct Answer :- a
Explanation : The impedance relay is better suited for phase-fault relaying for lines of moderate length than for either very short or very long lines. Arcs affect an impedance relay more than a reactance relay but less than a mho relay.
These hold characteristics of a plain impedance relay in a complex Z plane is a
The operating characteristic of a distance relay in the R–X plane is shown in the figure. It represent operating characteristic of a
Which of the following relays has inherent directional characteristics?
Differential relays are used for protection of
A three-phase transformer having zero sequence impedance of Z0 has the zero-sequence network as shown in the figure. The connection of its windings are
In Merz-Price percentage differential protection of a D- Y transformer, the CT secondaries connection in the primary and secondary winding of the transformer would be in the form of
Zero-sequence impedance of the transmission line is
The most commonly used method for the protection of 3–phase feeder is
For protection of parallel feeders fed from one end, the relays required are
An overhead transmission line is provided with earth wire for protection against.
Conductivity of aluminium, as compared to copper is
The type of insulators used on a 132 KV line are
Porcelain insulators are glazed to
Series capacitors are used to
The protection from negative sequence currents is provided for
A system which is more prone to faults is
PVC cables are usually used for
Earth wires are made of
The resistance ofearth should be
Transmission of power by ac cables is impossible beyond
For a high speed circuit breaker the total clearing time is around
The RRRV depends upon the
What is te preferred type of CB to be installed in extra high voltage ac system ?
The primary function of a fuse is to