400 Important Transmission and Distribution MCQ Question and Answer | PDF Free Download
1.For a short line if the receiving-end voltage is equal to sending-end voltage under loaded conditions
- AThe sending-end power factor is unity.
- BThe receiving-end power factor is unity.
- CThe sending-end power factor is leading.
- DThe receiving-end power factor is leading.
2.For an ac transmission line of length not exceeding 80 km, it is usual to lump the line capacitance at
- AThe sending end.
- BThe receiving-end.
- CThe midpoint.
- DAny convenient point.
3.Transmission efficiency of a transmission line increases with the
- ADecrease in power factor and voltage.
- BIncrease in power factor and voltage.
- CIncrease in power factor but decrease in voltage.
- DIncrease in voltage but decrease in power factor.
4.Under no-load conditions, the current in a transmission line is because of
- ACapacitance effect.
- BCorona effect.
- CProximity effect.
- DBack flow from earth.
5.Which of the following statements are correct?
- AFlow of unduly heavy current is Ferranti effect.
- BFerranti effect occurs under unloaded condition of line.
- CThe rise in receiving-end voltage is Ferranti effect.
- DBothe (b) and (c) combined is Ferranti effect.
6.In a long transmission line under no-load condition
- AThe receiving-end voltage is less than sending-end voltage.
- BThe sending -end voltage is less than receiving -end voltage.
- CThe sending -end voltage is equal to the receiving -end voltage.
- DNone of these.
7.Ferranti effect on long overhead lines is experienced when?
- AThe line is lightly loaded.
- BThe line is heavily loaded.
- CThe line is fully loaded.
- DThe power factor is unity.
8.Ferranti effect happens in transmission line when the line is
- AShort and loaded
- BLong and loaded
- CLong and unloaded
- DNone of these
9.The ABCD constants of a 3-phase transposed transmission line with linear and passive elements
- AAre always equal
- BNever equal
- CA and D are equal
- DB and C are equal
10.The values of A, B, C and D constants for a short transmission line are respectively
- AZ, 0, and 1
- B0, 1, 1 and Z
- C1, Z, 0 and 1
- D1, 1, Z and 0
11.For a transmission line with resistance R, reactance X and negligible capacitance, the generalised constant A is
- A0
- B1
- CR + jX
- DR + X
12.For a medium length transmission line, A is
- AEqual to B
- BEqual to C
- CEqual to D
- DNot equal to any of the above
13.For transmission line which one of the following relations is true?
- AAD ? BC = 1
- B? AD ? BC = 1
- CAD ? BC = ? 1
- DAD ? BC = 0
14.Which one of the following equations is CORRECT?
- A? AB + CD = ?1
- BAD + CD = 1
- CAB ? CD = ?1
- D?AD + BC = ? 1
15.The maximum efficiency in the transmission of bulk ac power will be achieved when the power factor of the load is
- ASlightly less than unity lagging
- BSlightly less than unity leading
- CUnity
- DConsiderably less than unity
16.A transmission line section shows an input impedance of 36 ohm and 64 ohm respectively, when short circuited and open circuited. What is the characteristic impedance of the transmission line?
- A100 ohm
- B50 ohm
- C45 ohm
- D48 ohm
17.A cable has inductance of 0.22 mH per km and capacitance of 0.202 mF per km. the surge impedance of the cable is
- A28 ohm
- B33 ohm
- C42 ohm
- D50 ohm
18.Which of the following statements is correct?
- ASurge impedance is the impedance at the time of breakdowns of voltage.
- BSurge impedance and characteristic impedance for a transmission line are the same.
- CSurge impedance is the impedance of transmission line when corona takes place.
- DNone of the above.
19.The characteristic impedance of a transmission line depends upon
- AShape of the conductor.
- BConductivity of the conductor material.
- CGeometrical configuration of the conductor.
- DNone of the above.
20.For a lossy transmission line, the characteristic impedance does not depend on
- AThe operating frequency of the line.
- BThe conductivity of the conductors.
- CConductivity of the dielectric separating the conductors.
- DLength of the line.