Electrical engineering Important Questions for HPCL | ISRO | GATE | BARC |ESE | UPPSC
Q1. A synchronous generator connected to an infinite bus is overexcited. Consider the only reactive power, from the point of view of the system, the machine acts as
- a) a capacitor
- b) an inductor
- C) a resistor
- d) none of these
Q2. The voltage stress will be maximum in an underground cable at
- a) The surface of the sheath
- b) The surface of the conductor
- c) The surface o the insulation.
- d) The surface of the armour.
Q3. The dielectric strength of air at a barometric pressure of 76cm and 25
degree centigrade is
- a) 30kv/ metre.
- b) 21.1kv rms/ cm.
- c) 21.1kv rms/ mm.
- d) 110kv / metre.
Q4. The positive sequence current of a transmission line is
- a) always zero
- b) one-third of negative sequence current
- c) three times the negative sequence current
- d) equal to negative sequence current
Q5. For the fault at the terminals of a synchronous generator, the fault current is maximum for a
- a) 3-phase fault
- b) 3-phase to ground fault
- c) Line-to-ground fault
- d) Line-to-line fault
Q6. The earth transformer is used to
- a) Avoid the harmonics in the transformers
- b) Provide artificial neutral earthing where neutral point is not accessible
- c)Improve stability of the system
- d) Measure the voltage
Q7. For differential protection of power transformer (delta-delta) the current transformers will have
- a) Delta-delta connection
- b) Star-delta connection
- c) Star-star connection
- d) Delta-star connection
Q8. For the protection of a very long extra high voltage line, the protective relay used is
- a) Over current with extremely inverse characteristics
- b) Percentage differential relay
- c) Reactance type distance relay
- d) Mho type distance relay
Q9. Resistance switching is normally employed in
- a) All breakers
- b) Bulk oil breaker
- c) Minimum oil breaker
- d) Air-blast circuit breaker
Q10. Symmetrical breaking capacity of ACB is
- a) Greater than asymmetrical breaking capacity
- b) Less than asymmetrical breaking capacity
- c) Equal to asymmetrical breaking capacity
- d) not related to asymmetrical breaking capacity
Q11. By which material the fuse element is generally made
- a) Copper
- b) Nickel
- c) Iron alloy
- d) Silver
Q12. Grounding is generally done in transmission line at
- a) The supply end
- b) The receiving end
- c) Middle of the line
- d) Anywhere
Q13. What is the approximate value of the surge impedance loading of a 400kV, 3-phase 50Hz overhead single circuit transmission line
- a) 230 MW
- b) 400 MW
- c) 1000 MW
- d) 1600 MW
Q14. When two identical first order systems have been cascaded non-
interactively the unit step response of the system will be
- a) Over damped
- b) Under damped
- c) Un-damped
- d) Critically damped
Q15. Which of the following methods is most strong tool to determine the stability and the transient response of the system ?
- a) Routh-Hurwitz criterion.
- b) Bode plot.
- c) Nyquist plot.
- d) Root locus.
Q16. If the gain of a critically damped system is increased, it will become
- a) Under damped system
- b) Over damped system
- c) Oscillatory system
- d) Critically damped system
Q17. Phase margin of a system is used to specify
- a) Relative stability
- b) Absolute stability
- c) Time response
- d) Frequency response
👉also read - Measurement instrument important question
👉Also check - 🔗ISRO Previous Years Electrical Engineering Questions
