101. A current transformer can be used with which of the following instruments?
a. Ammeter
b. Wattmeter
c. Watt hour meter
d. Any of the above
102. Voltage transformer of which class of accuracy can be used for precision testing in standard laboratories
a. 0.1 class
b. 10 class
c. 5.00 class
d. 1000 class
103. A transformer has primary to secondary turn ratio 0f 10. Every single ohm of reactance on secondary windings when referred to primary will be same as
a. 0.1 ohm
b. 1 ohm
c. 10 ohm
d. 100 ohm
104. For the same rating which of the following sets will be costly
a. Three phase transformer
b. Three transformers each of the single phase type
c. Both will have identical cost
105. Which of the following is not a flirting on the transformers
a. Breather
b. Conservator
c. Buchholz relay
d. Commutator
106. The reactance of a transformer depends on
a. size of the core
b. size of the tank
c. leakage flux
d. all of the above
106. If the frequency of supply voltage is doubled . Which loss will increase
a. eddy current loss
b. hysteresis loss
c. copper loss
d. none of the above
107. No load current in a transformer as a percentage of full load current is approximately
a. 25%
b. 15% to 20%
c. 5% to 10%
d. 1% to 3%
108. In a transformer maximum voltage regulation occurs when the power factor of the load is
a. unity
b. 0.5
c. lagging
d. loading
109. The regulation of a good transformer should be near
a. 1%
b. 10%
c. 50%
d. 100%
110. In a step up transformer which ratio has value of one
a. E2/E1 (e represent voltage )
b. I2/I1 ( i represent current )
c. F2/F1 ( f represent frequency )
