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


您可能感興趣的試卷

你可能感興趣的試題

1.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

2.單項選擇題Current measuring instruments must always be connected in ()

A.series with a circuit
B.parallel with a circuit
C.series-parallel with a circuit
D.delta with the shunt

3.單項選擇題The primary function of an electric motor is to ()

A.develop torque
B.generate high voltages
C.produce a magnetic field
D.generate high electrical resistance

4.單項選擇題The power factor at which a paralleled AC generator operates is usually adjusted by the ().

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