1. The area of the hysteresis loop will be least for one of the following materials. It is………
A.
wrought iron
B. hard steel
C. silicon steel
D.
soft iron
Answer - C
2. A current of 2 A passes though a coil of 350
turn wound on a ring of mean diameter 12 cm. The
flux density established in the ring is 1.4 wb/m2. Find
the value of relative permeability of iron……
A.
191
B.
600
C. 1200
D. 210 ᵡ 103
Answer - B
3. A bar of iron 1 cm2 in cross
section has 10-4 wb of magnetic flux in it. If µϒ=2000
what is the magnetic field intensity in the bar…….
A. 398×10-4 AT/m
B.
398 AT/m
C.796×10-3 AT/m
D. 398×104 AT/m
Answer - B
4. One sine wave has a period of 2 ms another has a period
of 5 ms and other has a period of 10 ms. Which sine wave is charging at a
faster rate ……..
A. sine wave with period 2 ms
B. sine wave with period of 5 ms
C.
all are at the same rate
D. sine wave with period of 10
ms
Answer - A
5. In a pure inductive circuit if the supply frequency is reduced
to ½ the current will…………..
A. be reduced by half
B.be
doubled
C.be four times as high
D. be reduced to one
fourth
Answer - B
6. There
are 3 lamps 40w, 100w and 60w. To realize the full rated power of the lamps
they are to be connected in………
A.
series only
B.parallel only
C.
series-parallel
D.
series or parallel
Answer - B
7. If in an RLC series circuit, the frequency is below the resonant
frequency, then…..
A.
XC =XL
B.
XC < XL
C.
XC = XL
D. none of the above
Answer -C
8. An RLC circuit has R=10 ohm L=2H. what value of capacitor will
make the circuit critically damped……..
A. 0.02 F
B. 0.08 F
C.
0.2 F
D. 0.4 F
Answer - B
9. When a series RL circuit is connector to a voltage source V at
t=0, the current passing through the inductor L at t =0+ is………
A.
V/R
B. infinite
C.
zero
D. V/L
Answer - C
10. Three wattmeter method of power measurement can be used to
measure power in…………
A.
Balanced circuits
B.
Unbalanced circuit
C.
Both balances and unbalanced
D. none of the above
Answer - C
11. Flat rate tariff
is charged on the basis of……
a. connected load
b. units consumed
c. maximum demand
d. both (i) and (ii)
Answer - b
12. For power factor
improvement, static capacitors have the drawback (s) of……
a. short service life
b. getting damaged by high voltage
c. not repairable
d. all of the above
Answer - d
13. Domestic consumers
are generally charged by……
a. simple tariff
b. flat rate tariff
c. block rate tariff
d.
maximum demand tariff
Answer - c
14. The brush voltage
drop in a d.c. machine is about …………
a. 0.1 V
b. 10 V
c. 2 V
d. 20 V
Answer - c
15. Small d.c.
machines generally have ………poles.
a. 4
b. 6
c. 2
d. 8
Answer - c
16 …….. d.c. machines
are most common.
a.2-pole
b. 4-pole
c. 6-pole
d. 8-pole
Answer - b
17. A triplex wave
winding will have ……… parallel paths.
a. 6
b. 2
c. 4
d. none of the above
Answer - a
18. High-voltage d.c.
machines use …….. winding.
a. lap
b. wave
c.
either lap or wave
d.
none of the above
Answer - b
19.
The yoke of a d.c. machine carries ,…….. pole flux.
a. the
b.
one-half of the
c. two
times the
d.
none of the above
Answer - b
20. The commutator
pitch for a simplex lap winding is equal to …….
a. number of poles of the machine
b. pole
pairs
c. 1
d. none of the above
Answer - c
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