In a given transformer for given applied voltage, losses which remain constant irrespective of load changes are______________?
(A) friction and windage losses
(B) copper losses
(C) hysteresis and eddy current losses
(D) none of the above
The use of higher flux density in the transformer design____________?
(A) reduces weight per kVA
(B) reduces iron losses
(C) reduces copper losses
(D) increases part load efficiency
In a transformer the tappings are generally provided on_____________?
(A) primary side
(B) secondary side
(C) low voltage side
(D) high voltage side
What will happen if the transformers working in parallel are not connected with regard to polarity ?
(A) The power factor of the two trans-formers will be different from the power factor of common load
(B) Incorrect polarity will result in dead short circuit
(C) The transformers will not share load in proportion to their kVA ratings
(D) none of the above
If the percentage impedances of the two transformers working in parallel are different, then______________________?
(A) transformers will be overheated
(B) power factors of both the transformers will be same
(C) parallel operation will be not possible
(D) parallel operation will still be possible, but the power factors at which the two transformers operate will be different from the power factor of the common load
If R2 is the resistance of secondary winding of the transformer and K is the transformation ratio then the equivalent secondary resistance referred to primary will be___________?
(A) R2/VK
(B) R2IK2
(C) R22!K2
(D) R22/K
Two transformers operating in parallel will share the load depending upon their____________?
(A) leakage reactance
(B) per unit impedance
(C) efficiencies
(D) ratings
The power transformer is a constant______________?
(A) voltage device
(B) current device
(C) power device
(D) main flux device
The purpose of providing iron core in a step-up transformer is?
(A) to provide coupling between primary and secondary
(B) to increase the magnitude of mutual flux
(C) to decrease the magnitude of mag-netizing current
(D) to provide all above features
Greater the secondary leakage flux____________?
(A) less will be the secondary induced e.m.f.
(B) less will be the primary induced e.m.f.
(C) less will be the primary terminal voltage
(D) none of the above