Saturday, September 12, 2015
Here we have Electrical Interview Questions On A.C. Transmission and Distribution ,MCQs On Power Electronics which are asked in most of the interviews and competitive exams like GATE (India),PGCET..etc.
Interview Question,Objectives on A.C. Transmission and Distribution:
Q1.With same maximum voltage between conductors, the ratio of copper volumes in 3-phase, 3- wire system and 1-phase, 2-wire system is
(a) 4/3
(b) 3/4
(c) 5/3
(d) 3/5
Q2. The volume of copper required for an a.c. transmission line is inversely proportional to
(a) current
(b) voltage
(c) power factor
(d) both (b) and (c)
(e) both (a) and (c).
Q3. For a.c. transmission lines less than 80 km in length, it is usual to lump the line capacitance at
(a) the receiving end
(b) the sending end
(c) the mid-point
(d) any convenient point.
Q4. Corona occurs between two transmission wires when they
(a) are closely-spaced
(b) are widely-spaced
(c) have high potential difference
(d) carry d.c. power.
Q5. The only advantage of corona is that it
(a) makes line current non-sinusoidal
(b) works as a safety-valve for surges
(c) betrays its presence by hissing sound
(d) produces a pleasing luminous glow.
Q6. The sag produced in the conductor of a transmission wire depends on
(a) weight of the conductor per unit length
(b) tension in the conductor
(c) length of the conductor
(d) all of the above
(e) none of the above.
Q7. Suspension insulators are used when transmission voltage is
(a) high
(b) low
(c) fluctuating
(d) steady
Q8. The string efficiency of suspension insulators can be increased by
(a) providing a guard ring
(b) grading the insulators
(c) using identical insulator disc
(d) both (a) & (b).
Q9. An interconnector between two generating stations facilitates to
(a) keep their voltage constant
(b) run them in parallel
(c) transfer power in either direction
(d) both (b) & (c)
Q10. The effective disruptive critical voltage of a transmission line does NOT depend on
(a) irregularity factor
(b) conductor radius
(c) distance between conductors
(d) material of the conductors.
Q11. By which of the following systems electric power may be transmitted?
(a) Overhead system
(b) Underground system
(c) Both (a) and (b)
(d) None of the above
Q12. ....... are the conductors, which cannect the consumer's terminals to the distribution
(a) Distributors
(b) Service mains
(c) Feeders
(d) None of the above
Q13. The underground system cannot be operatedabove
(a) 440 V
(b) 11 kV
(c) 33 kV
(d) 66 kV
Q14. Overhead system can be designed for operation upto
(a) 11 kV
(b) 33 kV
(c) 66 kV
(d) 400 kV
Q15. If variable part of annual cost on account of interest and depreciation on the capital outlay is equal to the annual cost of electrical energy wasted in the conductors, the total annual cost will be minimum and the corresponding size of conductor will be most economical. This statement is known as
(a) Kelvin's law
(b) Ohm's law
(c) Kirchhoff's law
(d) Faraday's law
(e) none of the above
Q16. The wooden poles well impregnated with creosite oil or any preservative compound have life
(a) from 2 to 5 years
(b) 10 to 15 years
(c) 25 to 30 years
(d) 60 to 70 years
Q17. Which of the following materials is not used for transmission and distribution of electrical power?
(a) Copper
(b) Aluminium
(c) Steel
(d) Tungsten
Q18. Galvanised steel wire is generally used as
(a) stay wire
(b) earth wire
(c) structural components
(d) all of the above
Q19. The usual spans with R.C.C. poles are
(a) 40–50 metres
(b) 60–100 metres
(c) 80–100 metres
(d) 300–500 metres
Q20. The corona is considerably affected by which of the following?
(a) Size of the conductor
(b) Shape of the conductor
(c) Surface condition of the conductor
(d) All of the above
We hope you enjoyed an objective test on A.C. Transmission and Distribution ,this is the collection of latest electrical interview,competitive exam questions,MCQs.