Rajasthan Polytechnic Third Year Paper 2016 – Switchgear and Protection

Rajasthan Polytechnic Third Year Paper 2016 – Switchgear and Protection

When all the three phases are short circuited, it gives rise to which type of current?
(a) Symmetrical Current
(b) Unsymmetrical Current
(c) Zero Current
(d) Fusing Current

The Fuse Rating is expressed in terms of
(a) Current
(b) Voltage
(c) VAR
(d) kVA

The operator ‘a’ rotates the vector through
(a) 90 Degree Clockwise
(b) 180 Degree anticlockwise
(c) 120 Degree anticlockwise
(d) 120 Degree Clockwise

To reduce short circuit fault currents ________are used.
(a) Reactors
(b) Resistors
(c) Capacitors
(d) None of the above

The Voltage appearing across the open contacts of the Circuit Breaker, after final arc extinction is called as
(a) Recovery Voltage
(b) Super Voltage
(c) Operating Voltage
(d) Peak Voltage

Breaking capacity of the circuit breaker is usually expressed in
(a) MVA
(b) MW
(c) Kilo-ampreres
(d) kV

Directional Relays are based on the flow of
(a) Power
(b) Current
(c) Voltage wave
(d) All of the above

Buchholz Relay is installed between
(a) Between Bushing and conductor
(b) Between Main Tank and Conservator
(c) Between Core and Winding
(d) None of the above

The most important stator winding fault of an alternator is
(a) Phase to Phase fault
(b) Inter-turn fault
(c) Earth fault
(d) All of the above

Which is the main Relay for protecting up to 90% of the transmission line-length in the forward direction?
(a) Directional over current relay
(b) Mho relay
(c) Carrier current protective relay
(d) Impedance relay