In a transformer if the frequency of the supply is varied then the magnetizing current in the core also varies.
a) True
b) False
Q.2.
CRGO Laminations in a transformer are used to minimize __________
a) eddy current loss
b) hysteresis loss
c) both eddy current and hysteresis loss
d) ohmic loss
Q.3.
A single phase transformer has emf per turn having 2310/V, 50Hz transformer asV. Then the estimated primary turns will be?
a) 189 turns
b) 179 turns
c) 176 turns
d) 190 turns
Q.4.
A single phase transformer has emf per turn having 2310/V, 50Hz transformer asV. The core area is(in square cm)?
a) 393
b) 277.8
c) 358.92
d) 450.03
Q.5.
If a transformer is fed from a dc rather than a 1-phase ac supply, then the transformer will __________
a) burn its windings
b) operate normal
c) will not operate
d) will give very small leakage flux
Q.6.
For a single phase transformer operating at normal operating conditions has useful flux of 1 Wb. If the machine is loaded at 0.8 p.f., then its mutual flux __________
a) may decrease to 0.98 Wb
b) remains constant
c) may increase 1.02 Wb
d) may decrease to 0.8 Wb
Q.7.
The flux involved in the emf equation of a transformer has __________
a) rms value
b) average value
c) total value
d) maximum value
Q.8.
If the frequency at the primary supply is varied gradually, then the secondary terminal voltage will __________
a) not change
b) vary directly
c) will vary oppositely
d) will vary inverse of frequency
Q.9.
There are two identical transformers A and B such that flux density applied to B is doubled. Then magnetizing current of B is?
a) larger than A
b) double of A
c) half of A
d) same as that of A.
Q.10.
A 20KVA, 2200/V,Hz single phase transformer has the below parameters:
a) 0.024 Ω
b) 0.06 Ω
c) 3 Ω
d) 7 Ω
Q.11.
A 20KVA, 2200/V,Hz single phase transformer has the below parameters:
a) 0.024 Ω
b) 0.06 Ω
c) 3 Ω
d) 7 Ω
Q.12.
A 20KVA, 2200/V,Hz single phase transformer has the below parameters:
a) 0.024 Ω
b) 0.06 Ω
c) 3 Ω
d) 7 Ω
Q.13.
A 20KVA, 2200/V,Hz single phase transformer has the below parameters:
a) 0.024 Ω
b) 0.06 Ω
c) 3 Ω
d) 7 Ω
Q.14.
In a transformer ______ decreases with increase of the leakage flux.
a) secondary terminal voltage
b) secondary induced voltage
c) primary induced voltage
d) all of the mentioned
Q.15.
The components needed to draw the phasor diagram of the transformer is?
a) A, B, C
b) B
c) B, C
d) A, B
Support mcqgeeks.com by disabling your adblocker.
Please disable the adBlock and continue. Thank you.