Electrical Systems Final Exam questions 100% correct answers

Materials that allow electricity to flow through them easily such as copper are called - correct answers Conductors Materials that don't allow electricity to flow through them easily are called - correct answers Insulators This is the measurement of electric current or flow of electrtons - correct answers Ampere This is the measurement of electromotive force or potential difference - correct answers Volts This is the measurement of resistance to the flow of electricity - correct answers Ohm This is a measurement of energy used per unit of time - correct answers Watt What is the Ohms Law Formula - correct answers V = IR What is electricity? - correct answers A type of energy fueled by the transferof electrons from positive to negative What is the difference between power and energy? - correct answers Power is energy at a specific time and energy includes a time constraint (Power * time) In a series circuit how do you calculate total resistance? - correct answers RT = R1 + R2 + R3 In a parallel circuit how do you calculate total resistance? - correct answers 1/RT = 1/R1 + 1/R2 + 1/R3 What do the acronyms AC & DC stand for and what is the main difference between the two? - correct answers Alternating Current & Direct Current. Electrons flow in one direction in DC and in AC they flow forward and then backward a little bit. What is the function of the hot wire? - correct answers The hot wire is the conductor providing volts. What is the function of the neutral wire? - correct answers It provides return path for the volts What is one reason that you would use three phase power? - correct answers It costs less to transport, motors are smaller and cheaper and & three phase has consistent power What are the two main reasons that we use AC current today? - correct answers It is cheaper and you can modify voltage The tighter the coil is on the transformer - correct answers the higher the voltage A cycle within electricity goes from 0-360 degrees how many cycles in a second is standard in the United States - correct answers 60 Hertz What two principles are key to a transformer - correct answers Electromagnetic & Electromagnetic induction Motors or computers on AC current systems can create an inductive load which caused a phase shift between the voltage and the current, because of this what is the result to power supply? - correct answers Power is waster What is apparent power? - correct answers Power available to use What is reactive power? - correct answers Garbage power, no work done What is a real power? - correct answers The power that actually does work A double circuit breaker will have 240 Volts of power on an electrical panel that has two 120 V hot bus barr. (T or F) - correct answers True At a power station what type of transformer will exist? - correct answers Step Up At residential and commercial locations what kind of transformers will exist? - correct answers Step Down With regards to a generator what is the function of an Uninterruptible Power Supply (UPS)? - correct answers It is used to make sure that at no point the power given to the generator stops With regards to a generator what is the function of an Automatic Transfer Switch (APS)? - correct answers It is used to transfer the power from your main power source to the generator and switches the generator on. The larger the gauge of a wire, - correct answers the smaller the diameter of the wire If you see conductors with brown, orange, or yellow insulation what would this tell you about the electricity within the conductor? - correct answers It is three phase voltage and has a higher voltage than 120 V WHat is a side effect that can occur from excessive voltage drop? - correct answers Improper or no function of the equipment, poor efficiency and wasted energy, and fire hazard Why does a large motor within building equipment require a motor starter? - correct answers To protect the equipment and because the inital startup of a motor can require more voltage Which steel conduit has the thickest wall? - correct answers Galvanized Rigid Conduit What is the correct order of distribution of electricity from the city power to the Air Handler Unit? - correct answers Switchgear, panel, subpanel, 240 V circuit, VFD