A: current
B: voltage
C: cycle time
D: frequency
举一反三
- Which of these is not an electrical quantity（） A: time B: voltage C: current D: power
- ( ) is not the index of power quality. A: voltage B: current C: frequency D: waveform
- The effective value of ac voltage or current is（ ） A: The average value of a voltage or current B: DC equal to the AC thermal effect is defined as the effective value of AC C: voltage or current are 0.707 of their amplitudes D: closely related to the frequency of alternating current
- Digital multi-meter cannot measure ( ) when the measured circuit is working. A: voltage B: current C: resistance D: None of the above
- It can be measured by HF9600E Multi-Function Power Meter（ ） A: Current RMS B: voltage RMS C: instantaneous power D: active power
内容
- 0
The voltage meter and current meter on the main switchboard shows ( <br/>). A: phase voltage and phase current of generator B: line voltage and line current of generator C: line voltage and line current of crane D: line voltage and line current of shore power
- 1
When the largest fault current occur after short fault () A: at the beginning time of the fault B: half cycle C: one cycle
- 2
Which value is valid for the iterate parameter in the CREATE_TIMER built-in function?（） A: CYCLE B: ITERATE C: NO_REPEAT D: REUSE
- 3
A transistor is a ( )operated device. A: voltage B: current C: both voltage and current D: none of the above
- 4
The function of direct current regulated power supply is to input an alternating current power of 220volts, so that it can output __________.( ) A: alternating current 200 volts voltage B: direct current 24 volts voltage C: direct current 200 volts voltage D: alternating current 24 volts voltage