Download Electrical Engineering Fundamentals (Interview Questions) and more Quizzes Electrical Engineering in PDF only on Docsity!
Electrical Engineering Fundamentals (Interview Questions)
What is Ohm's Law? V=IR, it describes the relationship between voltage, current and resistance What is charge? Value for electricity flowing in a circuit What is current? The rate of flow of charge What is voltage? pressure that pushes electricity through an electrical circuit What is resistance? opposition to flow What happens when two positively charged particles are placed next to each other? The charges will repel What is a valence electron? a valence electron is an outer shell electron that is associated with an atom What is the difference between analog and digital circuits? Analog circuits utilize continuous time signals, which means that an analog circuit has a response for almost every single value on the time signal. Digital circuits utilize a digital signal, which can only be represented as 0 (off) or 1 (on). There is only a response for these two states. How do voltage and current behave in a parallel circuit? Voltage stays the same, current divides proportionally. How do voltage and current behave in a series circuit? Voltage divides proportionally and current stays the same. What happens to current if the resistance in a series circuit doubles? The current will be reduced by half. What is DC current? Direct Current, a current that can only travel in one direction
What is AC current? Alternating Current, a current that can change directions What is a capacitor? a component that stores charge How do capacitors behave in series and parallel? Capacitors in parallel add up normally, but in series are the inverse of the sum of their inverses What do capacitors oppose? Capacitors oppose a change in voltage. This is due to the capacitor's time constant which makes it so that any sudden changes in voltage will be subjected to the capacitor having to charge first. How do capacitors behave at low and high frequencies? At low frequencies they act as an open circuit, and at high frequencies they act as a short. This is due to the capacitor's time constant where at low frequencies it takes the capacitor so long to charge it is like an open circuit, but at high frequencies it charges and discharges so quick it acts as a short. What is an inductor? A component that has the ability to concentrate a magnetic field How do inductors behave in series and parallel? Inductors in series are the inverse of the sum of their inverses, but in parallel add up normally What do inductors oppose? They oppose changes in current. How do inductors behave at low and high frequencies? At low frequencies, inductors become a short circuit, and at high frequencies it becomes an open circuit. How do you make a low pass filter? You connect a capacitor to ground between the source and the load, or an inductor in series between the source and the load. How do you make a high pass filter?
How does an AC generator work? A simple ac generator consists of a coil rotated in a magnetic field. As the coil rotates the magnetic field passing through it changes continuously, inducing a continuously changing voltage. The direction of the changing magnetic field in the coil changes every half rotation, so the sign of the induced voltage also changes every half rotation: the induced voltage is ac. What is an OpAmp? An opamp or operational amplifier is an integrated circuit that can amplify weak electric signals. What are the ideal characteristics of an OpAmp? infinite voltage gain, infinitely high input impedance, zero output impedance, gain independent of frequency, zero input voltage offset, positive and negative voltage swings to supply rails, output swings instantly to the correct value Why do we want infinite voltage gain in an ideal opamp? Since opamps are voltage amplifiers, the ideal opamp will want to amplify the incoming signal infinite times with the voltage going towards infinity Why do we want infinitely high input impedance in an ideal opamp? The lower the impedance, the higher the amount of current the opamp will draw. The higher the impedance the lower the amount of current the opamp will draw. We want the least amount of current drawn from the original circuit so that we can preserve the integrity of the original signal, hence an infinitely high input impedance. Why do we want zero output impedance in an ideal opamp? We want the amplified signal to preserve its full integrity along with its added power. An amount of output impedance would cause the signal to lose power and integrity. Why do we want gain independent of frequency in an ideal opamp? We want the opamp to behave the same way regardless of what the frequency of the input signal is so we can get the same gain for any signal. What is a transistor? A transistor is a semiconductor device comprised of an npn or pnp junction with a source, gate, and drain or emitter, base, and collector. A transistor can act as an electrical switch
which can turn on and off thousands of times a second. They are used in opamps for signal amplification as well as in digital circuits. What is a diode? A semiconductor device with two terminals, typically allowing the flow of current in one direction only. It is comprised of a pn junction. What is a rectifier? Apparatus that changes alternating current to direct current What is an FPGA? A field programmable gate array What are logic gates? Digital devices that control the passage of electrical signals from one part of a system to another. List as many logic gates as you can. And, or, not, xor, xnor, nand, nor What is the square root of - 1? i or j; this is referred to as a complex number If a transformer has more coils on its secondary it is a: Step up transformer How do you block out electromagnetic fields? With a faraday cage What is three phase power? Distributing the power work load between three wires, alongside a neutral wire (the ground). What is impedance matching and why is it important? Impedance matching is the process of designing the input or output of a system such that it delivers the most amount of electrical power. It is important to aid in reducing signal reflections from the load. What is the maximum power theorem?
