Description : What will happen if you increase the current in the motor?

**Answer** : Increasing current means increasing frequency of the motor because current is directly proportional to rotations of the motor rotor

Description : How can we increase the induced current?

**Answer** : Induced current can be increased by reducing no of windings on the secondary part compared to primary.

Description : For given applied voltage, with the increase in frequency of the applied voltage?

**Answer** : For given applied voltage, with the increase in frequency of the applied voltage eddy current loss will remain unchanged.

Description : Why does the speed of a DC shunt motor decrease as the load increases?

**Answer** : Because if the load is increasing then the torque must also be increase. If not then the speed of motor will decrease.

according to ohms law voltage directly proportional to current but it is reverse in transformer why?

Description : About trnsformer

**Answer** : Acc to Ohms law V=IR but it is only applicable when our resistance R is constant, as in case of transformer we take impedence which is equivalent to resistance is not constant it varies with system parameters that why Ohms law not applicable in case of transformer

Description : Why inductor current lags inductor voltage ?

**Answer** : Inductor is a wire wounding structure having a core material it induces emf which is opposite to the voltage supply and proportional to rate of change of current so current lags the voltage in inductor

Description : Which of the following is the least expensive protection for over current in low voltage system? (A) Rewireable fuse (B) Isolator (C) Oil Circuit breaker (D) Air break circuit breaker

**Answer** : Which of the following is the least expensive protection for over current in low voltage system? (A) Rewireable fuse (B) Isolator (C) Oil Circuit breaker (D) Air break circuit breaker

**Answer** : In order that current should flow without causing excessive heating or voltage drop, the relay contacts should have low contact resistance, be clean and smooth, be of sufficient size and proper shape.

Description : Analyze the effect of supply voltage on performance of LED as regards current, Lumen output, efficacy and life.

**Answer** : 1) Effect on Current:- In LED current depends upon supply voltage, if voltage get changes then current also change but this change in current will be control by resistors which are connected in series. 2) ... 4) Effect on Life:- If supply voltage is not stable then life of LED get reduced.

Description : With the help of N-channel JFET describe the effect of input voltage VGS on output current ID.

**Answer** : Working of N channel FET: * When a voltage is applied between the drain and source with a DC supply (VDD), the electrons flows from source to drain through narrow channel ... where the channel gets completely blocked and the drain current becomes zero is called pinch- off voltage.

Description : Define: i) Input Offset Voltage ii) Input offset Current iii) Input Bias Current iv) Output offset voltage

**Answer** : Definition of parameters of OPAMP is follows: i) Input Offset Voltage: Input offset voltage is defined as the voltage that must be applied between the two input terminals of an OPAMP to null or ... to ground) and output voltage is obtained non zero such voltage is output offset voltage of opamp.

Description : A linear network has a current input 4cos(ω t + 20º)A and a voltage output 10 cos(ωt +110º) V. Determine the associated impedance.

**Answer** : Solution

Description : Source transformation voltage source to current source and vice versa

Description : What kills, current or voltage?

**Answer** : Current would kill. You can actually have thousands of bolts going through you and not even know it. Yes you probably know already voltage is current times resistance. Since your body is a resistor it would take just a small amount of current to create a very high voltage

Description : Explain lagging quantity and leading quantity, explain this concept with voltage and current waveform

**Answer** : When two alternating quantities attain their respective zero or peak values simultaneously, the quantities are said to be in-phase quantities. When the quantities do not attain their respective zero or ... current is leading the voltage or the voltage is said to be lagging behind the current.

Description : Define: 1) voltage ratio, 2) current ratio, 3) transformation ratio of transformer.

**Answer** : 1) Voltage ratio: The voltages in primary and secondary winding is proportional to number of turns in primary and secondary respectively. So, the voltage ratio is same as transformation ratio. V2/V1 = N2 ... as transformation ratio of transformer. It is denoted by K. K = N2/N1

Description : Write the relation between phase and line current, phase and line voltage for Star connection.

**Answer** : Line voltage is equal to root three times of phase voltage and line and phase currents are equal in star connection

Description : A zener voltage regulator has load requirements of 12 V and 2 A. The zener diode minimum current requirement is 0.2 A. The minimum voltage at input is 24 V. What is the required value of series resistance with source? A) 5.45 Ω B) 6 Ω C) 7.2 Ω D) 6.38 Ω

**Answer** : A zener voltage regulator has load requirements of 12 V and 2 A. The zener diode minimum current requirement is 0.2 A. The minimum voltage at input is 24 V. What is the required value of series resistance with source? A) 5.45 Ω B) 6 Ω C) 7.2 Ω D) 6.38 Ω

Description : Step-down transformer converts high voltage and low current into: (A) How voltage and high current (B) High voltage and low current (C) Low voltage and high current (D) None of the above

**Answer** : Step-down transformer converts high voltage and low current into: Low voltage and high current

Description : A current controlled voltage source is equivalent to : (A) series voltage feed -back amplifier (B) shunt current feed -back amplifier (C) shunt voltage feed -back amplifier (D) series current feed -back amplifier

**Answer** : A current controlled voltage source is equivalent to : shunt voltage feed -back amplifier

Description : Which of the following theorems enables a number of voltage (or current) source to be combined directly into a single voltage (or current) source. (1) compensation theorem (2) reciprocity theorem (3) superposition theorem (4) Millman's theorem

**Answer** : Which of the following theorems enables a number of voltage (or current) source to be combined directly into a single voltage (or current) source. (1) compensation theorem (2) reciprocity theorem (3) superposition theorem (4) Millman's theorem

Description : A network that consists of at least a voltage source or current source is called A) Active network B) Ideal network C) Sourced network D) Outsourced network

**Answer** : A network that consists of at least a voltage source or current source is called Active network

Description : The internal resistances of an ideal current source, and an ideal voltage source are, respectively, (A) 0, ∞ (B) ∞, ∞ (C) ∞, 0 (D) 0,0

**Answer** : The internal resistances of an ideal current source, and an ideal voltage source are, respectively, ∞, 0

Description : A network is said to be under resonance when the voltage and the current at the network input terminals are (A) in phase (B) out of phase (C) in phase quadrature (D) in phase, and have equal magnitudes

**Answer** : A network is said to be under resonance when the voltage and the current at the network input terminals are in phase

Description : Electrical shock happens for voltage/current?

**Answer** : The severity ofelectric shockdepends on thecurrentflowing through the body, which is a function of the electromotive force (E) involts, and the contact resistance (R) in ohms.

Description : Why high voltage is used in power transmission?

**Answer** : The primary reason that power is transmitted at high voltages is to increase efficiency. ... The lower current that accompanies high voltage transmissionreduces resistance in the conductors aselectricity flows ... This means that thin, light-weight wires can beused in long-distance transmission.

Description : Why high voltage can reduce power loss?

**Answer** : when voltage has increased due to reduced current flow, thus power loss given by ( I^2R) will be low due to reduced current(I^2) provided that resistance (R) is constant.

Description : When a voltage of one volt is applied, a circuit allows one micro ampere current to flow through it. The conductance of the circuit is?

**Answer** : If v = 1 volt and i = 1 micro amp, i= 10^(-6) So R = V/I, R= 1/10^(-6) , R= 10^6 And now Conductance G = 1/R So G = 10^(-6) mho..... Answer

**Answer** : The size of a synchronous motor decreases with the increase in flux density.

Description : Reduction in core losses and increase in permeability are obtained with transformer employing?

**Answer** : Reduction in core losses and increase in permeability are obtained with transformer employing core built-up of laminations of cold rolled grain oriented steel.

Description : What are three ways you can increase the strength of an electromagnet?

Description : Why there is decrease in supply voltage with increase in drain current in voltage controlled current source circuit using op amp and mosfet?

Description : A sine wave voltage is applied across an inductor. When the frequency of the voltage is decreased, the current decreases.

**Answer** : The question seems to be wrong. Increase in frequency would actually decrease the current through the Inductor. This happens because inductive reactance Xl is directly proportional to frequency. And if frequency increases the value of Xl would ... vice versa. Xl= 2*pi*f*L I=E/Z Z=sqrt(R^2+Xl^2)

Description : Why does induction motor have high starting current?

**Answer** : In induction motor , the flux produce is quadrature to the applied voltage. Since when we are going to start motor , there is no flux present inside . So in order to lets say compensate it ... times of current to further increase flux. So that is reason for high starting current in induction motor

Description : What is the difference between line and phase current?

**Answer** : The currents flows through phase lines is called line voltage and currents flows from phase to neutral line is called phase current

Description : In voltage source converter based HVDC transmission system the active power is controlled by changing (A) phase angle of the converter ac input voltage (B) supply frequency of the converter ac input voltage (C) magnitude of the converter ac input voltage (D) DC voltage at the inverter terminals

**Answer** : In voltage source converter based HVDC transmission system the active power is controlled by changing phase angle of the converter ac input voltage

Description : Refer to the circuit below. The total absorbed (consumed) power is:

Description : Draw the Delta connected three phase system showing all the voltages and currents. Write the power equation.

Description : Draw the structural diagram of GTO. Explain briefly the switching behavior of GTO with the help of appropriate voltage and current waveform.

**Answer** : Gate Turn Off Thyristor (GTO) Conventional Thyristor can be turned on with gate terminal but can not turn off from gate terminal. But in case of Gate Turn Off Thyristor (GTO), we can turn it on and off ... subdivided as storage period (Ts), fall period (Tp) and tail period (Tt).

Description : What is the definition of extra low voltage?

**Answer** : Extra-low voltage (ELV) is an electricity supply voltage in a range which carries a low risk of dangerous electrical shock.

Description : What is the difference between line and phase voltage?

**Answer** : Line voltage is voltage between two phases R &Y (415 v) while phase voltage is the voltage between one phase and a neutral B & N (240 v).

Description : What is the difference between a line voltage and low voltage control system?

Description : What are the advantages of high voltage transmission?

**Answer** : Advantages: 1. As Transmission voltage increases, current decreases. 2. As current decreases, cross section of conductor decreases. 3. As cross section of conductor decreases ... line increases 12. As transmission voltage increases power handling capacity of transmission line increases