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.
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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.
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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.
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4. In case of open circuit transmission lines the reflection coefficient is
(a) 1.
(b) 0.5.
(c) -1.
(d) Zero.
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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.
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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.
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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.
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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°.
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9. When the transmission voltage increase, the percentage resistance drop
(a) increases.
(b) decreases.
(c) remain same.
(d) none of these.
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10. Power system is protected from lightning by use of
(a) lightning arrester.
(b) earthing mat.
(c) earth pit.
(d) earth riser.
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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.
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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.
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14. The value of safety factor of pin type insulator is
(a) 12.
(b) 10.
(c) 8.
(d) 7.
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15. Stability of a transmission line can be increased by
(a) shunt capacitor.
(b) series capacitor.
(c) shunt reactor.
(d) both 1 and 2.
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