Description : Can we apply Norton's theorem in an AC circuit?

Description : Can we apply the superposition theorem to AC circuit?

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

**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.

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

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

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

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

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

**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.

**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 : 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

**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?

**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 : 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

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

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

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

**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?

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

Description : Explain power in single phase AC circuit.

Description : Explain working of static AC circuit breaker.

**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.

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

**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?

**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?

**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 : 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

**Answer** : in parallel qith current source

Description : In any A.C. circuit always?

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

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

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

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

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

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

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

Description : Maximum Power Transfer Theorem 1

**Answer** : Maximum Power Transfer Theorem 1

Description : State Superposition Theorem.

**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.

**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 ?

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

Description : Why superposition theorem is not valid for power?

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

**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

**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

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

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

Description : Millman's theorem yields?

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

Description : The superposition theorem is applicable to?

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

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

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

**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

**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 : Which of the following motors can run on both AC and DC? A) Universal motor B) Dual wattage motor C) Flexible motor D) All the above

**Answer** : Which of the following motors can run on both AC and DC? A) Universal motor B) Dual wattage motor C) Flexible motor D) All the above

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

**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?

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

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

**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 : Why does a transformer only work with an AC supply?

**Answer** : The transformer work depends on the induction as main principle ,for that AC is the right means

Description : What is the direction of an AC current?

**Answer** : The magnitude and direction of alternating current is changes with respect to time. So for half cycle it is positive and for next half cycle it is negative.

Description : Can transformer convert AC to DC?

**Answer** : No, Transformer cannot convert AC to DC.

**Answer** : NO IT ONLY CONVERT FROM AC TO DC BECAUSE DIODE WHICH ARE USED IN IT, ARE UNIDIRECTIONAL.

Description : Thevenin’s theorem can be applied to network containing : (A) Passive elements only (B) Active elements only (C) Linear elements only (D) All of these

**Answer** : C