**Description :** Write the steps for finding the current through an element by Thevenin’s theorem.

**Last Answer :** Steps to find Thevenin's equivalent circuit, taking an example is as follows: 1. From the given circuit (fig.a),Remove RL from the terminals A and B and redraw the circuit as shown in ... (fig.d)from where it was temporarily removed earlier. Current flowing through RL is given by

**Description :** State maximum power transfer theorem for DC circuit.

**Last Answer :** Maximum power transfer theorem for DC circuit: The maximum power transfer theorem states that the source or a network transfers maximum power to load only when the load resistance is equal ... removed (disconnected) ii) All internal independent sources are replaced by their internal resistances.

**Description :** State the Thevenin’s theorem. Also write stepwise procedure for applying Thevenin’s theorem to simple circuits.

**Last Answer :** Thevenin's Theorem: Any two terminal circuit having number of linear impedance and sources (voltage, current, dependent, independent) can be represented by a simple equivalent circuit consisting of a single voltage ... 's equivalent circuit: Step V: Determination of Load current:

**Description :** State Thevenin’s Theorem.

**Last Answer :** Any two terminal circuit having number of linear impedances and sources (voltage, current, dependent, independent) can be represented by a simple equivalent circuit consisting of a single voltage ... circuit across the two terminals, when the sources are replaced by their internal impedances.

**Description :** While calculating Rth in Thevenin's theorem and Norton equivalent?

**Last Answer :** While calculating Rth in Thevenin's theorem and Norton equivalent all independent sources are made dead.

**Description :** In Thevenin's theorem, to find Z?

**Last Answer :** In Thevenin's theorem, to find Z all independent voltage sources are short circuited and all independent current sources are open circuited.

**Description :** All the rules and laws of D.C. circuit also apply to A.C. circuit containing?

**Last Answer :** All the rules and laws of D.C. circuit also apply to A.C. circuit containing resistance only.

**Description :** A parallel AC. circuit in resonance will?

**Last Answer :** A parallel AC. circuit in resonance will have a high impedance.

**Description :** In an AC. circuit, a low value of kVAR compared with kW indicates?

**Last Answer :** In an AC. circuit, a low value of kVAR compared with kW indicates high power factor.

**Description :** Explain working of static AC circuit breaker.

**Last Answer :** Static AC Circuit breaker: The circuit configuration of static AC circuit breaker using SCR is shown in the figure. When switch S' is closed, the SCRs T1 and T2 are fired in positive ... non-availability of gate current. Thus the maximum time delay for breaking the circuit is one half-cycle.

**Description :** Explain working of AC circuit breaker using SCR with circuit diagram.

**Last Answer :** AC Circuit Breaker: The circuit configuration of static AC circuit breaker using SCR is shown in the figure. When switch S' is closed, the SCRs T1 and T2 are fired in positive ... to non-availability of gate current. Thus the maximum time delay for breaking the circuit is one half-cycle.

**Description :** An AC supply of 230 V is applied to a half-wave rectifier circuit through a transformer having primary to secondary turn’s ratio 12:1. The peak inverse voltage is A) 8.62 V B) 12 V C) 19.17 V D) 27.11 V

**Last Answer :** An AC supply of 230 V is applied to a half-wave rectifier circuit through a transformer having primary to secondary turn’s ratio 12:1. The peak inverse voltage is A) 8.62 V B) 12 V C) 19.17 V D) 27.11 V

**Description :** An unshielded moving iron voltmeter is used to measure the voltage in an AC circuit. The stray DC magnetic field having a component along the axis will be (1) unaffected (2) decreased (3) increased (4) either decreased or increased depending on the direction of the DC field

**Last Answer :** An unshielded moving iron voltmeter is used to measure the voltage in an AC circuit. The stray DC magnetic field having a component along the axis will be either decreased or increased depending on the direction of the DC field

**Description :** What is the purpose of a capacitor in an AC circuit?

**Last Answer :** Every AC supply is not ideal AC it contains DC component so to provide restriction to DC component in supply we have to use Capacitor

**Description :** In an A.C. circuit power is dissipated in?

**Last Answer :** In an A.C. circuit power is dissipated in resistance only.

**Description :** The apparent power drawn by an A.C. circuit is 10 kVA and active power is 8 kW. The reactive power in the circuit is?

**Last Answer :** The apparent power drawn by an A.C. circuit is 10 kVA and active power is 8 kW. The reactive power in the circuit is 6 kVAR.

**Description :** The input of an A.C. circuit having power factor of 0.8 lagging is 40 kVA The power drawn by the circuit is?

**Last Answer :** The input of an A.C. circuit having power factor of 0.8 lagging is 40 kVA The power drawn by the circuit is 32 kW.

**Description :** Pure inductive circuit takes power from the A.C. line when?

**Last Answer :** It takes power when voltage decreases and current increases.

**Description :** In any A.C. circuit always?

**Last Answer :** In any A.C. circuit always apparent power is more than actual power.

**Description :** Application of Norton's theorem to a circuit yields?

**Last Answer :** Application of Norton's theorem to a circuit yields equivalent current source and impedance in series.

**Description :** Maximum Power Transfer Theorem 1

**Last Answer :** Maximum Power Transfer Theorem 1

**Description :** State Superposition Theorem.

**Last Answer :** Superposition Theorem: In any linear, bilateral, multisource network the voltage across or the current through any branch is given by algebraic sum of all individual voltages or currents caused ... sources acting alone with all other sources replaced by their internal resistances if any.

**Description :** State superposition theorem applied to D.C. circuits.

**Last Answer :** Superposition Theorem applied to D.C. circuits: Superposition theorem states that in any linear, bilateral, multisource network, the response (voltage across any element or current through any ... each source acting alone, while the other sources are replaced by their internal resistances.

**Description :** The superposition theorem is based on the concept of ?

**Last Answer :** The superposition theorem is based on the concept of Linearity.

**Description :** As per Shannon’s channel capacity theorem, if samples are transmitted in ‘T’ seconds over a noisy channel which is bandlimited to ‘B’ Hz. The number of samples ‘n’ is given by (symbols/notations carry their usual meaning) A) B/T B) T/B C) 2BT D) BT/2

**Last Answer :** As per Shannon’s channel capacity theorem, if samples are transmitted in ‘T’ seconds over a noisy channel which is bandlimited to ‘B’ Hz. The number of samples ‘n’ is given by ( ... /notations carry their usual meaning) A) B/T B) T/B C) 2BT D) BT/2

**Description :** Millman's theorem yields equivalent (1) Impedance or Resistance (3) Voltage source (2) Current source (4) Voltage or Current source

**Last Answer :** Millman's theorem yields equivalent Voltage or Current source

**Description :** Which of the following statements is incorrect ? (A) Superposition theorem is useful for Linear and Non-linear circuit analysis when several sources are present in the circuit. (B) ... purely resistive, maximum power transfer is achieved under the condition : Load Resistance = Source Resistance

**Last Answer :** Which of the following statements is incorrect ? (A) Superposition theorem is useful for Linear and Non-linear circuit analysis when several sources are present in the circuit. ... purely resistive, maximum power transfer is achieved under the condition : Load Resistance = Source Resistance

**Description :** Norton’s theorem states that a complex network connected to a load can be replaced with an equivalent impedance (A) in series with a current source (B) in parallel with a voltage source (C) in series with a voltage source (D) in parallel with a current source

**Last Answer :** in parallel qith current source

**Description :** The superposition theorem requires as many circuits to be solved as there are?

**Last Answer :** The superposition theorem requires as many circuits to be solved as there are sources.

**Description :** Millman's theorem yields?

**Last Answer :** Millman's theorem yields equivalent voltage or current source.

**Description :** The superposition theorem is applicable to?

**Last Answer :** The superposition theorem is applicable to linear responses only.

**Description :** The concept on which Superposition theorem is based is?

**Last Answer :** The concept on which Superposition theorem is based is linearity.

**Description :** Superposition theorem can be applied only to circuits having?

**Last Answer :** Superposition theorem can be applied only to circuits having linear bilateral elements.

**Last Answer :** According to Lami's theorem if three forces acting at a point are in equilibrium, each force is proportional to the sine of the angle between the other two.

**Description :** A large AC generator, supplying power to an infinite bus, has a sudden short-circuit occurring at its terminals. Assuming the prime mover input and the voltage behind the transient reactance to remain constant immediately after the fault, acceleration of the generator rotor is

**Last Answer :** A large AC generator, supplying power to an infinite bus, has a sudden short-circuit occurring at its terminals. Assuming the prime mover input and the voltage behind the transient reactance ... , acceleration of the generator rotor is inversely proportional to the moment of inertia of the machine

**Description :** Explain the principle of ON-OFF control and phase control of AC voltage controller with suitable circuit and waveforms.

**Last Answer :** The integral cycle control (on-off control) and phase angle control are the two types of AC voltage controller. The principle of ON-OFF control: The on-off control is also called an integral cycle ... control. In phase control, the switch is on for some period of each cycle.

**Description :** In an ac series RLC circuit, the voltage across R and L is 20 V; voltage across L and C is 9 V and voltage across RLC is 15 V. What is the voltage across C?

**Last Answer :** In an ac series RLC circuit, the voltage across R and L is 20 V; voltage across L and C is 9 V and voltage across RLC is 15 V. What is the voltage across C? 7 V

**Description :** Alternating current (AC)

**Last Answer :** AC stands for Alternating Current meaning voltage or current that changes polarity or direction respectively over time. An Alternating Current (AC) is an electric current whose magnitude ... energy are known as alternators and are simpler construction than DC electromechanical generators.

**Description :** Why are DC motors used in trains and not AC motors ?

**Last Answer :** The reason is torque. torque is inversely proportional to speed..i.e when th knowe train comes to rest position to motion.. initial speed is zero..so it requires high starting torque for ... current will flow through field and armature coils then maximum torque is available at the intial condition.

**Description :** Why is AC considered more efficient than DC?

**Last Answer :** Ac is more efficient than dc because it is easy to maintain and change the voltage of ac for transmission and distribution purpose. Plant cost of ac transmission is much lower compared to dc transmission. When fault occurs it is easy to interrupt ac supply.

**Description :** Which is more dangerous AC or DC and why ?

**Last Answer :** Dc is more dangerous than Ac because in Ac the voltage will varies but in dc the constant voltage

**Description :** Why is AC better for long distance power transmission than DC ?

**Last Answer :** ac is more economical to transmit for long distances . wires can be made smaller by step up transformer .. since major cost are wires to transmit .. then at the end of distance step down transformer is used for commercial use.

**Description :** Why can't we store AC in batteries instead of DC ?

**Last Answer :** Because the direction of the current changes in AC electricity, you cannot directly store the power. Placing a capacitor in an AC circuit has no effect on the alternating flow of the electricity. The only ... is indirectly, by storing DC and then using a power inverter to convert the DC to AC.

**Description :** What is the conversion between. AC to AC ? DC to DC? AC to DC? DC to AC ?

**Last Answer :** 1.ac to ac is regulation 2.dc to dc is chopper 3.ac to dc is rectifier 4.dc to ac is inverter

**Description :** AC generator

**Last Answer :** A.C power can be generated as a single phase or as a balanced poly-phase system. However, it was found that 3-phase power generation at 50 Hz will be economical and most suitable. Present day three phase generators ... has uniform air gap (figure 2.1(b)) and used when speed is high.

**Description :** Define : i) Average value ii) RMS value of an AC Wave.

**Last Answer :** i) Average value: The average value is defined as the average of all instantaneous values during one alternation . That is, the ratio of the sum of all considered instantaneous values to the ... as produced by the alternating current when flowing through the same resistance for the same time.

**Description :** Is the power line voltage available in our homes a dc or an ac voltage?

**Last Answer :** The power line voltage available in our homes is AC. Mobile dwellings are the most commonly DC-supplied homes and even then they tend to include AC supply for heavier loads.

**Description :** AC Circuits with Resistance but No Reactance

**Last Answer :** AC Circuits with Resistance but No Reactance AC Circuits with Resistance but No Reactance Series resistances let two resistances R 1 and R 2 are connected in series as shows in figure and there ... voltage. Voltage V A is common to both the branch hence voltage V A is common reference.

**Description :** What is the need of polarity marking in polyphase AC circuits?

**Last Answer :** Need of Polarity Marking in Polyphase AC Circuits: i) Polarity marking of terminals provides reference polarity for better understanding of system, even if the polarity of ac voltage changes ... of current transformers in relay protection circuit and getting desired performance is very difficult.

**Description :** Explain how sinusoidal AC voltage is generated by using simple one loop generator.

**Last Answer :** An electric current produced by means of electrical machine is known as generator which converts mechanical energy into electrical energy. When conductor cuts the magnetic flux, emf induced in it. (Faraday' ... upon position of armature. The nature of emf is alternating as shown by the waveform.