Electrical Engineering Practice bits -6
1.
As the frequency increase, the skin
effect
a.
Decreases
b.
Remain same
c.
Increases
d.
All the above
2.
The number of insulator disc required to
form a string for 400kv line around
a.
15-16
b.
22-23
c.
25-27
d.
30-34
3.
At hilly areas the corona loss
a.
Increases
b.
Decreases
c.
Remain in same
d.
None
4.
In transmission lines we usually use
cross arms made of
a.
Aluminium
b.
Copper
c.
Steel
d.
RCC
5.
Between two supports, due to sag the
conductor takes the form of
a.
Semi circle
b.
Caternary
c.
Hyper bola
d.
None
6.
Moving iron instruments are used in
a.
Ac only
b.
DC only
c.
AC and DC
d.
All the above
7.
Fuse wire have
a.
High melting point
b.
Low inductance
c.
Low melting point
d.
High resistance
8.
SWG stands for
a.
Standard wire group
b.
Simple wire group
c.
Standard wire gauge
d.
Simple wire gauge
9.
If a power factor of a circuit is unity,
its reactive power is
a.
Zero
b.
Unity
c.
Maximum
d.
Minimum
10.
____ motor is used for electric traction
a.
DC series motor
b.
DC shunt motor
c.
Both A and B
d.
None
11.
AC magnets are made of laminated iron to
a.
For better induction
b.
to reduce eddy current losses
c.
for AC and DC used
d.
to reduce reluctance
12.
A 2KW ,200 V dc generator will supply a
load current of
a.
2Amp
b.
5 Amp
c.
20 Amp
d.
10Amp
13.
The synchronous speed of an 8 pole
induction motor induction motor operates at 50Hz supply is
a.
3000rpm
b.
1000rpm
c.
1500rpm
d.
750rpm
14.
Commutator in a dc motor
a.
Converts DC to AC
b.
Converts AC to DC
c.
Invert AC to DC
d.
Invert DC to AC
15.
What is the unit of magnetic flux density
a.
flux
b.
Tesla
c.
Ampere turn
d.
W b
/m
16.
One metric horse power is equal to
a.
735.5 watts
b.
746 watts
c.
760 watts
d. 700 watts
d. 700 watts
17.
The trade name of transformer oil
a.
ASKARAL
b.
CASTROL
c.
INDANE
d.
CRB
18.
A 3-phase 20 KVA load is having 0.8
lagging power factor. The true power of the circuit is
a.
16KW
b.
36KW
c.
48KW
d.
75KW
19.
Secondary of current transformer will
have
a.
More turns a thick gauge
b.
Less turns of thin gauge
c.
More turns of thin gauge
d.
Less turns of thick gauge
20.
What is the unit of Reactive power
a.
KW
b.
KVAR
c.
KVA
d.
All the above
