106. A current transformer
A. should have its secondary open while the primary is carrying current
B. should never have its secondary open while the primary is carrying current
C. is never used with the secondary circuit closed through ammeters, wattmeters, current coils or relay coils
D. may keep the secondary circuit closed without any serious trouble
107. If the secondary winding of current transformer is left open
A. there will be no current in the primary
B. current transformer will blast
C. no damage will result
D. there will be only magnetizing component of current in the primary
108. Instrument transformers are used in ac system for help in the measurement of
A. current and voltage
B. power and energy
C. power factor
D. all of these
109. For an instrument transformer, the ratio error is defined as
A. rated primary current/rated secondary current
B. nominal ratio-actual ratio/actual ratio
C. actual ratio/nominal ratio
D. actual ratio-nominal ratio/nominal ratio
110. Schering bridge is used to measure
A. resistance
B. frequency
C. input voltage
D. capacitance and its power factor
111. The dielectric loss of a capacitor can be measured by
A. Wien bridge
B. Owen bridge
C. Schering bridge
D. Maxwell bridge
112. Anderson bridge
A. requires a standard inductor in terms of which the loss angle of the capacitor is expressed
B. is applicable for precise measurement of capacitances
C. is applicable for precise measurement of inductances of over a wide range of values
D. requires a standard resistor in terms of which the self inductance is expressed
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