Nate Electrical Exam Questions and Complete Solutions Graded A+

What electro-mechanical control would you use on a cap tube or automatic expansion valve system to maintain the space temperature? - Answer: C: A thermostatic control Open motors are designed to operate at a given temperature rise as indicated on the motor nameplate. What does this mean? - Answer: A: indicates the temp. rise over the surrounding air of a motor when the motor is operating at full-load conditions A voltmeter is connected into a circuit in which of the following ways? - Answer: B: Parallel A low pressure control is usually located on the: - Answer: A: Condensing unit A high pressure control is usually located on the: - Answer: A: Condensing unit The term "nominal voltage" refers to: - Answer: D: The listed voltage Which of the following is a safety control? - Answer: B: High pressure control Low voltage controls are usually designed to operate at no more than: - Answer: A: 25 volts A unit of power equal to one horsepower and delivered at the shaft of a motor is known as: - Answer: B: Brake horsepower What is the purpose of the holding circuit in a magnetic motor starter? - Answer: B: Holds the main contacts closed until the control circuit through the interlock is broken. On a magnetic motor starter, the alloy piece that causes the motor starter to open and shut off the motor if too much motor current is drawn is called the: - Answer: D: Trip armature A set of contacts in a pressure control that close when the pressure increases are - Answer: A: Direct acting Direct acting means "closes on rise". Contacts close on an increase Which of the following control settings is typically non-adjustable? - Answer: B: Range Ohm's law states: - Answer: A: E = IR All else being equal, which of the following wire sizes will carry the most current? A: 10 ga B: 14 ga C: 12 ga D: 18 ga - Answer: A: 10 ga The run capacitor on a motor is used to: - Answer: A: Increase torque Doubling the voltage to a resistance will cause the power or watts to: - Answer: C: Quadruple What is impedance? - Answer: A: Opposition to alternating current flow How are fuses sized? - Answer: A: By amperage C: By voltage Capacitors are rated in: - Answer: B: Microfarads C: Volts One horsepower is equal to _______ watts. - Answer: B: 746 How much resistance must be placed in a 220-volt circuit to limit the current to 2 amps? - Answer: B: 110 ohms Impedance in a circuit is the result of: A: Pure resistance B: Inductive reactance C: Capacitive reactance D: All of the above - Answer: D: All of the above Doubling the voltage to a fixed resistance will: - Answer: B: Cause the current to double When the temperature of a negative temperature coefficient material increases, its resistance will: - Answer: C: Decrease What is the Btuh output of an electric heater rated at 15 Kw? - Answer: B: 51,150 Btuh What is the total capacitance of two 20-microfarad capacitors wired in series with each other? - Answer: B: 10 mf What is the total capacitance of two 20-microfarad capacitors wired in parallel with each other? - Answer: D: 40 mf If a conductor is wrapped around the jaws of a clamp-on ammeter four times and the meter indicated 16 amps, the actual amperage would be: - Answer: C: 4 amps On a standard electro-mechanical thermostat, if the fan switch is in the "on" position, the indoor fan will: - Answer: C: Run continuously Which of the following capacitors is the best choice to replace a 35 mf, 370 volt run capacitor? A: 35 mf, 330 volt B: 35 mf, 390 voltC: 30 mf, 440 volt D: 40 mf, 370 volt - Answer: B: 35 mf, 390 volt A motor is a ________ load. - Answer: B: Inductive The compressor oil safety control is an electro-mechanical control that operates on which two pressures? - Answer: A: Oil pump pressure and suction pressure What is the millivolt reading of a good thermocouple? - Answer: B: 15 mv A high pressure safety control is: - Answer: B: Reverse acting