- H11Q10 - Phase A is indicated on the diagram of the electrical system. The identification of the other wire indicated is:
- H11Q7 - The grounded wire of the electrical system of Questions 5 and 6 is required to be marked with white tape or some other means. The electrical code also requires the top wire of that same delta system to be marked with the color:
- H11Q8 - A 10 horsepower, 230 volt, single-phase electric motor draws 50 amperes of full-load current. If a 10 horsepower, 230 volt 3-phase electric motor is operated from a 230 volt 3-phase system, the expected full-load current drawn by the motor will be approximately:
- H11Q4 - The missing voltage for the electrical system is
- H11Q13 - You go to an electrical panel and find that there are three ungrounded conductors entering the main circuit breaker. There is also an insulated wire a few sizes smaller entering the neutral lug marked with white tape. Using a voltmeter, the following voltages are measured: Phase A to Phase B 202 V Phase A to Phase C 202 V Phase B to Phase C 202 V Phase A to Neutral 117 V Phase B to Neutral 117 V Phase C to Neutral 117 V
- H11Q15 - The above electrical system that is an open delta, 3-phase electrical system is:
- H11Q16 - The above electrical system that could provide power at 277 volts and 480 volts is:
- H11Q12 - The current drawn by a 15 kW 3-phase, 240 volt electric resistance heater is: (What is the power factor of a resistance load?) ( P = E*I*pf*1.73 )
- H11Q9 - A 3-phase electric motor draws 24 amperes at 230 volts with a power factor of 0.85. The power in watts being drawn by the motor is: (P=E*I*pf*1.73)
- H11Q2 - The missing voltage for the electrical system is
- H10Q7 - For a transformer supplying power to a dwelling providing the customer with both 120 volts and 240 volts, the utility code requires the utility to connect the middle wire to a ground rod. The National Electrical Code requires the middle wire to also be connected to a ground rod when it enters the customer electrical service panel. That middle wire supplying the customer service has a name which is the:
- H10Q9 - Two single-pole circuit breakers are shown connected side-by-side. The voltage that can be measured between the output screws of the circuit breakers when the breakers are on is:
- H10Q11 - Refer to the diagram above. The voltage that can be measured between main lugs "A" and "B" is:
- H11Q6 - The missing voltage for the electrical system is
- H10Q15 - Examine the diagram of the previous question. Assume the neutral wire became broken somewhere between the service panel and the two lamps. The voltage measured across the 60 watt lamp would be expected to be:
- H10Q12 - Refer to the diagram above. The voltage that can be measured between main lug "B" and the neutral terminal block is:
- H10Q14 - Two lamps are supplied by a typical 120/240 volt electrical system except the 60 watt lamp is supplied from "hot" wire A, and a 100 watt lamp is supplied from "hot" wire B. Both lamps are supplied by the same neutral wire. The voltmeter is measuring the voltage across the terminals of the 60 watt lamp. The voltage expected will be:
- H9Q18 - A transformer has a 1 to 2 turns ratio, and the primary winding is energized at 100 volts. Two 50 ohm resistors connected in series are connected across the secondary winding of the transformer as shown in the diagram. The current flowing through the resistors will be
- H9Q17 - A single-phase transformer has a rating of 112.5 kVA. If the output voltage of the transformer is 240 volts, the transformer full load current rating on the secondary will be:
- H11Q1 - The missing voltage for the electrical system is