1. Voltage regulation of a generator at low power factor will be
(A) higher.
(B) lower.
(C) unchanged.
(D) none of these.
Answer ⇓
2. The rated voltage of a 3 phase power system is given as
(A) rms phase voltage.
(B) peak phase voltage.
(C) peak line to line voltage.
(D) rms line to line voltage.
Answer ⇓
3. Ferranti effect takes place at
(A) light load.
(B) no load.
(C) full load.
(D) light load or no load.
Answer ⇓
4. The designed of feeder is mainly depend on
(A) its current carrying capacity.
(B) voltage drop in it.
(C) operating voltage.
(D) operating frequency.
Answer ⇓
5. The designed of distributors are generally depend on
(A) its current carrying capacity.
(B) operating voltage.
(C) voltage drop in it.
(D) operating frequency.
Answer ⇓
6. Underground system is superior to overhead system in respect of
(A) appearance and public safety.
(B) maintenance cost.
(C) frequency of faults, power failure and accidents.
(D) all of the above.
Answer ⇓
7. The main disadvantage of underground system over overhead system is
(A) exposure to lighting.
(B) heavy initial cost.
(C) high losses.
(D) more maintenance.
Answer ⇓
8. The main drawback of overhead system over underground system is
(A) more flexible.
(B) higher charging current.
(C) surge problem.
(D) high initial cost.
Answer ⇓
9. The mostly used circuit breaker for short line fault without switching resistor is
(A) oil circuit breaker.
(B) air blast circuit breaker.
(C) SF6 breaker.
(D) vacuum circuit breaker
Answer ⇓
10. In a three-phase system, the voltages are separated by
(A) 45°.
(B) 90°.
(C) 120°.
(D) 180°.
Answer ⇓
11. In a three-phase system, when the loads are perfectly balanced, the neutral current is
(A) zero.
(B) one-third of maximum.
(C) two-thirds of maximum.
(D) at maximum.
Answer ⇓
12. The circuit breakers produce least arc energy is
(A) air blast CB.
(B) air break CB.
(C) minimum oil CB.
(D) plane oil CB.
Answer ⇓
13. The designed of insulation of the modern EHV lines is based on
(A) corona.
(B) voltage drop.
(C) switch voltage.
(D) lighting voltage.
Answer ⇓
14. A constant load power means a uniform conversion of
(A) mechanical to electrical energy.
(B) electrical to mechanical energy.
(C) current to voltage.
(D) voltage to current.
Answer ⇓
15. Air blast circuit breaker is most suitably used upto
(A) 132 kV.
(B) 260 kV.
(C) 400 kV.
(D) none of the above.