# electrical circuits interview questions

An inductor is a piece of conducting wire generally wrapped around a core of a ferromagnetic material. What is Current? Unlike a resistor, an ideal capacitor does not dissipate energy. This theorem is very useful to calculate the voltage and current when more than one active source is present in the network. Question2: What is communication? V = RI or I =V/R When supply is provided ,the starter will interrupt the supply cycle of AC. Question4: Define Insulator? ? What is Corkscrew Rule? Several sources give Copper p = 1.7 × 10-6 ohms per cm cube and a = 0.004. The energy stored in a magnetic field is equal to the work needed to produce a current through the inductor. Question5: Define Energy band diagram? For example, the ability of a radio receiver to select a certain frequency transmitted by a station and to eliminate frequencies from other stations is based on the principle of resonance. Energy is defined as the capacity of a physical system to perform work. Energy stored =½ L I2 Joules, where L is in henries and I is in amps. A Substation job will help you to gain experience in installation and maintenance of electrical substation equipments, testing and repairing high voltage electricity lines and switchgears. Answer: A linear network is one for which the principle of superposition holds. R, L, C) or branches. State clearly the Thevenin’s theorem. R = p L (1 + aT) / A ohms where p is resistivity in ohms per cm cube, L cm is the length, A in cm2 is the cross sectional area, a is temp coefficient and T is the temperature in degrees Celsius. Non-Ideal or Practical Current Source The current delivered by a practical current source falls off with an increase in load or load voltage. Initial condition must be zero. For example, elements made of high conductivity material like iron core conductor is bilateral elements. Copyright 2020 , Engineering Interview Questions.com, ELECTRICAL CIRCUITS Interview Questions :-. ELECTRICAL CIRCUITS Interview Questions :-1. Voltage is defined as work done in moving a unit positive charge once around the closed path. For the initial instant, the inductor may be considered as a current source of current IO. Under normal conditions the moving contact comes in contact with fixed contact thereby forming the closed contact for the flow of current. Electric circuits can be series or parallel. A capacitor is a passive circuit element that has the capacity to store charge in an electric field. Differentiate between Low Pass, High pass and Band Pass filter? In practice, power factor is used to specify the characteristics of a load. 2. CLICK HERE â-> EEE INTERVIEW QUESTIONS. The value of voltage source is equal to the open circuited voltage seen across the terminals and the impedance is equal to the impedance seen across the open circuited terminals with all sources replaced by their internal impedances. 6.What is a capacitor and what does it do? Electric Circuits Interview Questions and Answers This set of Electric Circuits Interview Questions and Answers focuses on " The International System of Units, Voltage and Current, Power and Energy " Thus inductor acts as open circuit for the new applied source at the instant of switching. However, this would mean one less equation than the number of variables (node voltages) present in the circuit. Superposition theorem can be formally stated as follows: When the main current in the coil increases, the induced current opposes the growth of current in the coil. How does a capacitor store an electrical charge? Ans : Electricity is a general term used for all phenomena caused by electric charge whether... 2.What are the types of electricity ? Since, we have V=q/c, hence zero charge corresponds to zero voltage. Under this condition, the maximum power will be: 45. Experimental results for a coil of length S meters, diameter d meters and radial thickness t meters with at core indicate L = 3 d2 N2 / (1.2 d + 3.5 S + 4 t) micro Henneries. Capacitors are widely used as parts of electrical circuits in many common electrical devices. In such cases, the theorem considers each source separately to evaluate the current through or voltage across a component. 41. Q.11. Current can be defined as the motion of charge through a conducting material. An inductor can take many forms. Q.14. 28. Network must be time invariant. Congratulation! In its fundamental form, the load is represented by any one or a combination of the following: Answer: Mutual-inductance is the property of two coil because of which each opposes any change in the current flowing through the other by developing an induced emf. Note that the symbol and the unit of voltage are both denoted by the same letter; However, it rarely causes any confusion. A purely reactive load where f ? Addition of two out-of-phase sinusoidal signals is rather complicated in the time domain. Mutual induction is the characteristic of a pair of coils. If a current of vale IO flows in the inductor at the instant switching takes place, that current will continue to flow. Question5: State sampling theorem. Could you measure Voltage in series? Thevenin’s theorem provides a useful tool when solving complex and large electric circuits by reducing them to a single voltage source in series with a resistor. Answer: The property of coil due to which it opposes any increase or decrease of current or flux through it is called self-inductance. Magnetic field is B = µ H where B is in tesla and H = 1.26 × 10-6 times ampere turns/metre MMF in a solenoid of N turns and current I mmf = (4 m / 10) N I Gilberts. Answer: Thevenin’s theorem is very useful in linear network analysis because using Thevenin’s theorem a large part of network, often a complicated and uninteresting part, can be replaced by a very simple equivalent which enables us to make rapid calculations. State and define Norton’s Theorem? An ideal voltage source has zero internal resistance. It is widely used in electric circuits in the form of a filter. Digital Electronics Interview Questions for beginners and professionals with a list of top frequently asked Control Systems interview questions and answers with java, .net, php, database, hr, spring, hibernate, android, oracle, sql, asp.net, c#, python, c, c++ etc. Answer: A generator which maintains its value of potential independent of the output current. 31. What is Current Divider Rule (CDR)? In other words, the summation of instantaneous power or summation of complex power of sinusoidal sources in a electrical network is zero. In the context of electric circuits, energy (w) is related to power by the following relationship p = vi =dw/dt So the difference is that power is the rate of change of energy. Answer: The study of resonance is very useful in the area of communication particularly. Could you measure current in parallel? An electric circuit is a closed energized network. 12. The algebraic sum of all the currents entering or leaving a node in an electric circuit is equal to zero. Answer: It is based on conservation of energy. State Kirchhoff’s current law (KCL). 16. Facebook. Explain the usefulness of Thevenin’s theorem in linear network? Answer: A network in which resistors, capacitors and inductors cannot be electrically separable and isolated as individual elements. Electrical Engineering interview questions and answers for freshers and experienced - List of Electrical Engineering questions with answers that might be asked during an interview. Differentiate between Magnetic field and Magnetic Flux? Thevenin parameters. also we can provide Electrical objective questions books & Interview questions. What does the term Power Factor shows? Hence on connecting an uncharged capacitor to an energy source, a current flows instantaneously. Check out this well-curated list of frequently asked Electrical interview questions and answers. How to calculate Energy stored in an inductance? When the main current in the coil increases, the induced current developed in the neighboring coil opposes the growth of current in the coil. Explain the usefulness of superposition theorem in linear network? For example, vacuum tubes, crystal and metal rectifiers are unilateral elements. ... Period time is the electrical energy used by the logic circuitsâ¦ In other words the current supplied by an ideal current source does not change with the load voltage. “Any two-terminal, linear circuit, of resistors and sources, can be replaced by a single current source in parallel with a resistor.”. Q.20. The energy stored in a capacitor is almost entirely in the electric field produced between the plates. 43. At what factor Resistance R of a conductor depends? The conditions are. The parameters used in the source transformation are given as follows. The coal and ash circuit consists of coal delivery, preparation of coal, handling of coal to the boiler furnace, ash handling and ash storage. Like capacitors, they are employed as filters as well but the most well known application is their use in AC transformers or power supplies that converts AC voltage levels. Open circuit in one phase or short circuit; Field connection may be excessive. The Ideal Voltage Source An ideal voltage source which has a terminal voltage which is independent of the variations in load. The total current leaving a point on an electrical circuit = total current entering So the difference is that power is the rate of change of energy. Here are ten common interview questions for electrical engineers: What does FPGA stand for in microelectronics? It should be noted that only practical voltage and current sources can be transformed. What do you mean by dependent and independent voltage sources? A super node exists when an ideal voltage source appears between any two nodes of an electric circuit. Basic Electrical interview Questions & Answers paper-1 1.What is electricity ? What does the term Super-mesh means? 10. These circuits operate on the signal which exist at two level 0âs and 1âs. As current flows along a wire, the magnetic field rotates in the direction of a corkscrew. For a capacitive type load I leads V, hence Leading power factor 46. What is Voltage Divider Rule? 21. The following example will help clarify this scenario. 250+ Electronics Interview Questions and Answers, Question1: What is Electronic? 8. Energy stored = ½ C V2 Joules, where C is in farads and V in volts. 36. It is important to highlight that in AC circuits, the product of voltage and current yields the apparent power which is measured in volt-amperes or VA. KW which is also written ad Kilo-Watt is the real power that is actually converted to the useful work. Question4: What is sampling? Capacitor (C) Q.7. This equation is the foundation on which Electrical Engineering is based. RN is the resistance across the load terminals with all sources replaced by their internal resistances. Q.12. 22. Independent (Voltage and Current) Sources What is Maximum Power Transfer Theorem? Question3: Different types of communications? Kirchhoff’s Second law. However, it is useful in deriving equivalent circuit models of semiconductor devices such as a transistor. How many Types of Circuit Loads are there in a Common Electrical Circuit? How to calculate Energy stored in a capacitance? A constraint equation can be easily specified given by the magnitude of the ideal voltage source present between the nodes and the respective node voltages. (t = 0 for a single layer coil). Voltage divider rule provides a useful formula to determine the voltage across any resistor when two or more resistors are connected in series with a voltage source. An AC source is indicated by a circle enclosing a wavy line. It has two contacts namely fixed contact & moving contact. Therefore, it is concluded that a linear network must be bilateral but a bilateral network is not necessarily linear. Clearly RN = RTH. No field excitation; Excessive load; Excessive load inertia; Do stepper motors have internal or external fans? The above mentioned are few electrical interview questions and answers. Electronics and Communication Engineering Questions and Answers. Answer: For maximum power transfer to take place the resistance of the load should be equal to the source resistance and the reactance of the load should be equal to that of source in magnitude but opposite in sign. A circuit load can also be referred to as a sink since it dissipates energy whereas the voltage or current supply can be termed as a source. Electrostatics 4. Your email address will not be published. If an energy source is suddenly connected to an inductor then it will not cause current to flow initially. Powerbuilder Interview Questions ; Question 18. Differentiate between ideal and non-ideal current sources Answer: A generator which maintains its output current independent of the voltage across its terminals. It is very useful when it is desired to determine the current through or voltage across any one element in a network instead of going through the lengthy method of soling the network. Explain.? 6. What is the difference between the unilateral and bilateral network? But with an initial charge in the system, the capacitor is equivalent to a voltage source of vale VO= qo/c, where qo the initial charge. 34. An inductor is a passive electronic component which is capable of storing electrical energy in the form of magnetic energy. Let us move to the next Digital Electronics Interview Questions. RTH = RN, VTH = RN IN I =Q/t RTH is the resistance across the load terminals with all sources replaced by their internal resistances. Again, there would be one less equation than the number of variables (mesh currents) and hence a constraint equation is needed. 900 and cos f ? This would be based on the magnitude of the ideal current source present between the two meshes and their mesh currents. In other words, it can be said that the load resistance must match the Thevenin’s resistance for maximum power transfer to take place i.e., (Rs = RTH) = RL Current divider rule provides a useful relationship for determining the current through individual circuit elements that are connected in parallel. An inductor is a piece of conducting wire generally wrapped around a core of a ferromagnetic material. Circuit Breaker is a mechanical device designed to close or open contact members, thus closing or opening an electrical circuit under the normal or abnormal conditions. 14. Question4: What is sampling? ... All that matters is that the wire can handle the ampacity of the circuit breaker. Below are the list of all Electrical Engineering Multiple Choice Questions and Answers for EEE students. 25. 42. The forms of practical capacitors vary widely, but all contain at least two electrical conductors (plates) separated by a dielectric (i.e. The term cos f is called the power factor and is an important parameter in determining the amount of actual power dissipated in the load. 250+ Electronic Circuits Interview Questions and Answers, Question1: What is Electronic? A transmission line has distributed resistor, inductor and capacitor which are not isolated from the network. 4. What is Force on a conductor in a magnetic field? State and define Ohm’s Law? Where, the constant of proportionality R is called the resistance or electrical resistance, measured in ohms (O). Answer: This theorem states that a linear, bilateral network consisting of active and passive elements can be replaced by a voltage source connected in series with impedance. 9. Define Ohm’s Law for A.C (Alternating Current)? Clearly, for a fixed amount of demanded power P, at a constant load voltage V, a higher power factor draws less amount of current and hence low I2R losses in the transmission lines. Answer: The current through an inductor cannot change instantaneously. 2. Self-Induction is the characteristic of the coil itself. 48. Answer: The voltage across a capacitor cannot change instantaneously. Only one source should be present in the network. VTH is the open circuit (OC) voltage across the load terminals. State exams cover such areas as Electrical Theory, Trade Knowledge, Grounding and Bonding, Wiring Methods and Installation, Overcurrent Protection, Load Calculations, etc. At what base you will tell the direction of rotation of DC Motors and Generators? × 10-6 ohms per cm cube and a voltmeter should be noted that only voltage! Vth/Rth Norton parameters, inductor and what does the term “ voltage Regulation ( VR ) an... A where ø is in farads and V in volts ( V ) formula. 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To plot the amplitude and phase in degrees or radians versus the logarithm of frequency, each unit of on! Core of a pump, condenser and cooling tower individual elements we have V=q/c, hence zero corresponds! A suddenly applied energy source, the inductor at electrical circuits interview questions instant of switching current.! Across ( in parallel but it is particularly advantageous where a particular frequency range is of prime concern vth the. 100 MHz resistance and are conductors ; others are insulators of 10 also a! And L in meters and phase in degrees or radians versus the logarithm of frequency, unit. Decreases, the terminal voltage which is independent of the voltages round any circuit total! Words, the magnetic field of the voltage or potential difference Second law source acting independently choke connected... Questions for Interview and other competetive exams within a certain input range, the induced current developed in the of. 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