A. If the speed of rotation of conductor in a
magnetic field is increased, the induced voltage
1. increases
2. decreases
3. remains constant
4. reaches zero
1. increases
2. decreases
3. remains constant
4. reaches zero
B. flux
remaining same If the cross-sectional area of a magnetic field is increased,
the flux density also
1. decreases
2. increases
3. remains the same
4. becomes zero
2. increases
3. remains the same
4. becomes zero
C. Eddy current losses of transformer depends
upon
1. Power factor
2. load
3. voltage
4. frequency
D. For maximum efficiency of transformer Iron loss
1. is equal to copper loss
2. is greater than copper loss
3. is zero
4. is less than copper loss
E. for an isolation transformer(k=transformation ratio)
1. k=2
2. k=0
3. k=1
4. k=0.5
F. A transformer steps up or steps down the voltage without change in
1.
current
2.
voltage
3.
frequency
4.
none of the above
G. for a transformer 440v/220v the number of turns in primary winding is 100,no of turns in secondary winding is:
1.
300
2.
25
3.
50
4.
200
H. for a
transformer 440v/220v ,the frequency of voltage in primary is 50hz ,then
frequency of emf induced in secondary winding will be:
1.
300
2.
25
3.
50
4.
200
I. The variable losses in a transformer is
1. Hysteresis loss
2. core losses
3. copper losses
4. eddy curent loss
J. Transformer core is made with silicon content to/for
1. reduce hysteresis loss
2. core losses reduction
3. copper losses reduction
4. reduce eddy curent loss
