1. The function of steel wire in a ACSR conductor is
(a) to take care of surges.
(b) to prevent corona.
(c) to reduce inductance and hence improve power factor.
(d) to provide additional mechanical strength.
Answer
2. In high voltage transmission lines the top most conductor is
(a) R-phase conductor.
(b) Y- phase conductor.
(c) B-phase conductor.
(d) earth conductor.
Answer
3. If the spacing between two conductor is increased, the corona effect in transmission line
(a) increases.
(b) decreases.
(c) remains same.
(d) none of the above.
Answer
4. In case of open circuit transmission lines the reflection coefficient is
(a) 1.
(b) 0.5.
(c) -1.
(d) Zero.
Answer
5. ACSR is used in place of copper in overhead line because of
(a) higher current carrying capacity.
(b) being lighter in weight.
(c) economy.
(d) higher tensile strength.
Answer
6. The type of insulators used on 132 kV transmission lines is
(a) pin type.
(b) disc type.
(c) shackle type.
(d) pin and shackle type.
Answer
7. In power system, the string efficiency can be improved by
(a) using Longer cross arm.
(b) grading the insulator.
(c) using a guard ring.
(d) any of the above.
Answer
8. The charging current in a transmission line
(a) lags the voltage by 90°.
(b) leads the voltage by 90°.
(c) leads the voltage by 120°.
(d) lags the voltage by 120°.
Answer
9. When the transmission voltage increase, the percentage resistance drop
(a) increases.
(b) decreases.
(c) remain same.
(d) none of these.
Answer
10. Power system is protected from lightning by use of
(a) lightning arrester.
(b) earthing mat.
(c) earth pit.
(d) earth riser. Answer
11. A bus bar is rated by
(a) current only.
(b) current and voltage only.
(c) current, voltage, frequency.
(d) current, voltage, frequency and short time current.
Answer
12. Galvanised steel wire is generally used as
(a) stay wire.
(b) earth wire.
(c) structural components.
(d) all of the above.
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13. A booster is a
(a) series wound generator.
(b) shunt wound generator.
(c) synchronous generator.
(d) none of the above.
Answer
14. The value of safety factor of pin type insulator is
(a) 12.
(b) 10.
(c) 8.
(d) 7.
Answer
15. Stability of a transmission line can be increased by
(a) shunt capacitor.
(b) series capacitor.
(c) shunt reactor.
(d) both 1 and 2.
Answer