單項選擇題Why is it desirable to operate paralleled AC generators at the same power factor?（）

A.Circulating currents are kept to a minimum
B.Field excitation losses are kept to a minimum
C.Generator rotors will have a lesser tendency to hunt
D.Because a power factor increase will decrease kilowatt output


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1.單項選擇題An ammeter should be used to measure （）

A.the voltage between two points in a circuit
B.circuit continuity
C.current flow in a circuit
D.total or partial circuit resistance

2.單項選擇題When the voltage remains constant and the resistance is increased in a series circuit, the flow of current （）

A.increases by the square of the original value
B.increases
C.remains the same
D.decreases

3.單項選擇題The power factor of an AC generator operating singularly is determined by the （）

A.connected load
B.prime mover speed
C.field excitation
D.generators rated voltage

4.單項選擇題The resistance of electric wire will decrease as its （）

A.length increases
B.cross-sectional area increases
C.temperature increases
D.percent of metallic purities increases

5.單項選擇題The total power consumed in a parallel circuit is （）

A.the sum of the powers used in each load (resistor)
B.divided by the number of loads
C.always less than the power used in the smallest load
D.the sum of the powers used in each individual load never more than the power used in the largest load