Question 1

Overhead lines generally use

Accepted Answer

A)  copper conductors
B)  all aluminium conductors
C)  A.C.S.R. conductors
D)  none of these C

Question 2

The conductors of the overhead lines are

Accepted Answer

A)  solid
B)  stranded
C)  both solid and stranded
D)  none of the above B

Question 3

The material commonly used for sheaths of underground cables is

Accepted Answer

A)  lead
B)  rubber
C)  copper
D)  iron A

Question 4

Transmission line insulators are made of

Accepted Answer

A)  glass
B)  porcelain
C)  iron
D)  P.V.C.

Question 5

Large industrial consumers are supplied electrical energy at

Accepted Answer

A)  400 V
B)  11 kV
C)  66 kV
D)  400 kV

Question 6

The distributors for residential areas are

Accepted Answer

A)  single phase
B)  three-phase three wire
C)  three-phase four wire
D)  none of the above

Question 7

Transmitted power remaining the same, if supply voltage of a D.C. 2-wire feeder is increased 100 percent, saving in copper is

Accepted Answer

A)  25 percent
B)  50 percent
C)  75 percent
D)  100 percent

Question 8

The loads on distributors systems are generally

Accepted Answer

A)  balanced
B)  unbalanced
C)  either of the above
D)  none of the above

Question 9

Distribution lines in India generally use

Accepted Answer

A)  wooden poles
B)  R.C.C. poles
C)  steel towers
D)  none of the above

Question 10

For an overhead line, the surge impedance is taken as

Accepted Answer

A)  20-30 ohms
B)  70-80 ohms
C)  100-200 ohms
D)  500-1000 ohms

Question 11

High voltage transmission lines use

Accepted Answer

A)  suspension insulators
B)  pin insulators
C)  both (a)  and (b) 
D)  none of the above

Question 12

In transmission lines the cross-arms are made of

Accepted Answer

A)  copper
B)  wood
C)  R.C.C.
D)  steel

Question 13

The material generally used for armour of high voltage cables is

Accepted Answer

A)  aluminium
B)  steel
C)  brass
D)  copper

Question 14

The material commonly used for insulation in high voltage cables is

Accepted Answer

A)  lead
B)  paper
C)  rubber
D)  none of the above

Question 15

The presence of ozone due to corona is harmful because it

Accepted Answer

A)  reduces power factor
B)  corrodes the material
C)  gives odour
D)  transfer energy to the ground

Question 16

The minimum clearance between the ground and a 220 kV line is about

Accepted Answer

A)  4.3 m
B)  5.5 m
C)  7.0 m
D)  10.5 m

Question 17

Most of the high voltage transmission lines in India are

Accepted Answer

A)  underground
B)  overhead
C)  either of the above
D)  none of the above

Question 18

The power factor of industrial loads is generally

Accepted Answer

A)  unity
B)  lagging
C)  leading
D)  zero

Question 19

Which of the following is usually not the generating voltage ?

Accepted Answer

A)  6.6 kV
B)  8.8 kV
C)  11 kV
D)  13.2 kV

Question 20

A uniformly-loaded D.C. distributor is fed at both ends with equal voltages. As compared to a similar distributor fed at one end only, the drop at the middle point is

Accepted Answer

A)  one-fourth
B)  one-third
C)  one-half
D)  twice

Exam 2: Electrical Supply and Distribution