Objectives On Transformer.1.4 | MCQs On Transformer | All Students World


1).The basic function of a transformer is to change
a)    The power level
b)    The power factor
c)    The level of the voltage
d)    The frequency

2). The core in a large power transformer is built of
a)    cast iron
b)    mild steel
c)    ferrite   
d)    silicon steel  

3).The frequency of voltage at the secondary is
a)    Greater then the primary    
b)    Equal to primary
c)    Less then primary
d)    Any of the above

4).The low voltage winding of a 400/230 V single phase 50 Hz transformer is to be connected to keep the magnetizationcurrent at the same level in both the cases the voltage at 25 Hz should be
a)    230 V   
b)    460 V
c)    115 V
d)    65 V

5). power input to the transformer on no load at rated voltage comprises predominantly
a)    copper losses  
b)    hysteresis losses
c)    core losses
d)    eddy current losses

6) the transformer has maximum efficiency when the ratio of iron to copper losses is equal to
a)    2
b)    1
c)    1.5
d)    0.5

7).Tappings of a transformer are provided
a)    at the phase end of LV side  
b)    at the middle of HV side
c)    at neutral side end of HV side
d)    at the phase end of HV side

8).In which transformer,the tertiary winding is used?
a)    Star -Delta
b)    Delta-Star
c)    Star-Star
d)    Delta-Delta

9).The main purpose of using core in a transformer is to
a)    Decreasing iron losses
b)    Preventing eddy current losses
c)    Eliminate magnetic hysterises    
d)    Deacrease the reluctance of the common magnetic circuit.

10).In an auto transformer,Power is transferred through ?
a)    Induction process
b)    Conduction process
c)    Both a and b
d)    Non of the above