With a purely resistance load the voltage and current are in phase, giving a power factor of ().
A、one
B、less than one
C、more than one
D、negative one
A、one
B、less than one
C、more than one
D、negative one
A、both meters in series with the resistance B、both meters in parallel with the resistance C、the ammeter in series and the voltmeter in parallel with the resistance D、the ammeter in parallel and the voltmeter in series with the resistance
A、A.both meters in series with the resistance B、B.both meters in parallel with the resistance C、C.the ammeter in series and the voltmeter in parallel with the resistance D、D.the ammeter in parallel and the voltmeter in series with the resistance
A、A.increase in resistance with increased temperature B、B.increase in resistance with decreased temperature C、C.decrease in resistance with increased temperature D、D.increase in conductance with increased temperature
A、higher boiling temperature for a given pressure than does a pure refrigerant B、lower boiling temperature for a given pressure than does a pure refrigerant C、boiling pressure equal to that of a pure refrigerant at a given pressure D、boiling point will not be affected by entrained oil
A、resist changes in viscosity with changes in temperature B、resist emulsification C、neutralize acids D、resist oxidation at high temperatures
A、A.shunt B、B.high-resistance coil in the armature circuit C、C.low-resistance coil in the armature circuit D、D.shunt and a coil of high resistance
A、heat-resisting acrylic B、heat-resisting aluminum C、insulating varnish D、insulating white lead