1 Answer

Answer :

The voltage regulation in magnetic amplifier type voltage regulator is effected by varying the reactance.

Related questions

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  

Last 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 : A transformer has negative voltage regulation when its load power factor is   (1) Zero (2) Unity (3) Leading (4) Lagging

Last Answer : 0

Description : Identify the increasing order of voltage regulation of the following dc generators a same load :  (A) differential compound, shunt and under compound  (B) shunt, differential compound and ... C) under compound, shunt and differential compound  (D) shunt, under compound and differential compound

Last Answer : Identify the increasing order of voltage regulation of the following dc generators a same load : under compound, shunt and differential compound 

Description : Negative voltage regulation is indicative that the load is?

Last Answer : Negative voltage regulation is indicative that the load is capacitive.

Description : A good voltage regulation of a transformer means?

Last Answer : A good voltage regulation of a transformer means output voltage fluctuation from no load to full load is least.

Description : Minimum voltage regulation occurs when the power factor of the load is?

Last Answer : Minimum voltage regulation occurs when the power factor of the load is leading.

Description : The voltage gains of the amplifier with and without feedback are 20 and 100 respectively. The percentage of negative feedback would be

Last Answer : The voltage gains of the amplifier with and without feedback are 20 and 100 respectively. The percentage of negative feedback would be 4%

Description : An amplifier has a voltage gain of 120. To reduce distortion, 10% negative feedback is employed. The gain of the amplifier with feedback is  (1) 141 (2) 92.3 (3) 9.23 (4) 1.41

Last Answer : An amplifier has a voltage gain of 120. To reduce distortion, 10% negative feedback is employed. The gain of the amplifier with feedback is 9.23

Description : The voltage gain of a common -source JFET amplifier depends up on its  (1) Input impedance (2) Amplification factor (3) Dynamic drain resistance (4) Drain load resistance

Last Answer : B

Description : Describe the functional pin diagram of regulator IC 78XX and 79XX.

Last Answer : IC 78XX: Explanation: 78XX series of IC regulators is representative of three terminal devices that are available with several fixed positive output voltages. It has three terminals labeled ... can also use 25μF aluminum electrolytic capacitor. Values given may be increased without limit. 

Description : Enlist names of regulator IC’s .

Last Answer : 1. Fixed Voltage Regulators IC - a. Positive voltage regulator IC’s - 78XX series eg. 7805, 7812 etc.  b. Negative voltage regulator IC’s - 79XX series eg. 7905, 7912 etc.  2. Adjustable Voltage Regulator - LM317 is example of positive adjustable voltage regulator.

Description : What is regulator ? State its need.

Last Answer : A voltage regulator is a circuit or device designed to deliver a constant voltage at its output regardless of changes in ac supply voltage and load current. Need:- A voltage regulator is one ... unexpected result or damage one of the components in the circuit, hence voltage regulator is needed.

Description : What are the disadvantages of the linear regulator? how are they overcome in the switching regulator? What is continuous and discontinuous mode switching regulator?

Last Answer : Disadvantages of the linear regulator: Linear regulator waste power in the form of heat. Linear regulator has very low efficiency. Linear regulator cannot be used for the step ... between continuous mode and discontinuous mode switching regulator.

Last Answer : It is simply variable resistance create opposition to flow of current and decrease or increase the speed of fan

Description : what is linear regulator?

Last Answer : linear regulator video

Description : Define line regulation and load regulation.

Last Answer : Load regulation is the ability of the power supply to maintain its specified output voltage over changes in the load. Line regulation is the ability of the power supply to maintain its specified output voltage over changes in the input line voltage.

Description : Classify hydro-electric power plants according to water flow regulation and explain in brief.

Last Answer : Classification of hydro-electric power plants according to water flow regulation of water flow:-  1. Large reservoir power plant 2. Run-off river (ROR) power plant with poundage 3. Run-off River ... depends upon rate of flow of water Initial cost is less Its purpose is to generate electricity.

Description : Define load and line regulation.

Last Answer : 1. Load regulation : The load regulation indicates how much the load voltage changes when the load current changes. The load regulation is defined as:  % Load regulation = (VNL-VFL) / VFL *100  ... the power supply. A well-regulated power supply can have a line regulation of less than 0.1%.  

Description : The unit of speed regulation of a governor is :  (A) Hz (B) Hz/MW (C) Hz/MVA (D) rpm/MVAR

Last Answer : The unit of speed regulation of a governor is : Hz/MW

Last Answer : A transformer can have regulation closer to zero on leading power factor.

Description : A ferro resonant transformer regulation is also known as?

Last Answer : A ferro resonant transformer regulation is also known as constant current transformer.

Description : About trnsformer

Last 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 : working of class B push pull amplifier.

Last Answer : Circuit Diagram:- Operation:  In class B amplifier transistor conduct only for half cycle of input signal.One conduct in positive half cycle and other conducts in negative half ... Then output transformer joins these two halves and produces a full sine wave in the load resistor. 

Description : Compare amplifier and oscillator.

Last Answer : Figure shows a block diagram of an amplifier and an oscillator.   An amplifier is a device, which produces an output signal with similar waveform as that of the input. ... is supplied. An oscillator does not require any external signal to start or maintain energy conversion process.

Description : role of tuned LC circuit in tuned amplifier.

Last Answer : In order to pick up and amplify the desired radio frequency signal, the resistive load in the audio amplifier is replaced by a tuned circuit (also called a parallel resonant circuit)as shown ... desired radio frequency signal. (ii)Amplification of the selected signal to a suitable voltage level.

Description :  applications of RC coupled amplifier

Last Answer : Applications of RC coupled amplifier: (i) Widely used as Voltage amplifiers. (ii) They are used in Public Address System. (iii) In Tape recorders. (iv) In stereo amplifiers (v) In T.V. V.C.R. and C.D. Players.

Description : characteristics of Hi-Fi amplifier system.

Last Answer : Characteristics of HI-FI amplifier: 1. Signal to noise ratio should be better than 50dB. 2. Frequency response should be flat within +-1dB. 3. Nonlinear distortion should not be more ... provided. 6. Environmental conditions should be such as to eliminate the external noise in listening room. 

Description :  two stage amplifier and need of multistage amplifier.

Last Answer : Circuit diagram of two stage amplifier : Need of multistage amplifier: The output from a single stage amplifier is usually insufficient to drive an output device. So that ... to second amplifier.  To increase the overall gain of the amplifier multistage amplifier is needed.

Description : advantages and disadvantages of direct coupled amplifier over RC coupled amplifier. 

Last Answer : Advantages:  Due to absence of coupling capacitors, the gain does not reduce on the lower frequency side.  This amplifier can amplify dc signals. Reduced cost and complexity due to absence of ...   The output waveform has a dc shift.  Poor frequency response at a higher frequency.

Description :  transformer coupled amplifier

Last Answer :  transformer coupled amplifier

Description : Single stage CE amplifier

Last Answer : Requirement(Necessity) of Multistage amplifier: -In many applications we required a high gain. But sometimes gain produced by an amplifier is not sufficient so to increase the gain, we ... necessity of multistage amplifier is for providing high gain. It is also required for high bandwidth.

Description : Give the different types of amplifier coupling.

Last Answer : 1. Resistance – capacitance (RC) coupling.  2. Inductance (LC) coupling.  3. Transformer coupling (TC)  4. Direct coupling (D.C.)

Description : State the need of multistage amplifier. Draw frequency response of R-C coupled amplifier.

Last Answer : The need of multistage amplifier The voltage (or power) gain, obtained from a single stage small signal amplifier, is limited. Therefore, it is not sufficient for all practical applications. Therefore, in ... to use a MULTISTAGE AMPLIFIER .  Frequency response of R-C coupled amplifier.

Description : Define gain and bandwidth of an amplifier.

Last Answer : Bandwidth  The range of frequency over which the voltage gain is equal to or greater than 70.7% of its maximum value Gain: The ratio of output parameter (voltage/ current /power) to the input parameter (voltage/ current /power) of an amplifier is known as gain. It is denoted by a letter A

Description : Draw diagram of class A push-pull amplifier and explain its operation. 

Last Answer : Class A Push-pull Amplifier: The circuit diagram of class A push-pull amplifier is as shown in the fig.(a). Operation: The resistors R1 and R2 along with Vcc provide the dc biasing so as ... Vcc is applied to the collectors of transistors Q1 and Q2 through the centretapped output transformer. 

Description : State the need of cascade amplifier and draw circuit diagram of 2-stage direct coupled amplifier.

Last Answer : Need:- The voltage (or power) gain, obtained from a single stage small signal amplifier, is limited. Therefore, it is not sufficient for all practical applications. Therefore, in order to obtain greater voltage and power gain, cascade amplifiers are used.

Description : Compare RC coupled, transformer coupled and direct coupled amplifier based on four points.

Last Answer : Parameter RC coupled Transformer coupled Direct coupled  Coupling element Resistor and capacitor Transformer No element Impedance matching Poor Excellent good Frequency ... Low frequency amplifier,opamp Size and cost small Large and bulky least

Description : List the advantages of RC coupled amplifier.

Last Answer : Advantages: 1. The frequency response is excellent 2. The circuit is very compact and extremely light 3. Cost is low because it employ resistors and capacitors which are cheap 

Description : State the need of cascade amplifier.

Last Answer : Most systems a single transistor amplifier does not provide sufficient gain or bandwidth or will not have the correct input or output impedance matching. Hence cascade amplifier is use which consist more than one stages of amplification.

Description : A differential amplifier has a differential gain of 28000 and CMRR is 60 dB. What will be the value of common mode gain? A) Ac = 0.125 B) Ac = 0.33 C) Ac = 3 D) Ac = 28 

Last Answer : A differential amplifier has a differential gain of 28000 and CMRR is 60 dB. What will be the value of common mode gain? A) Ac = 0.125 B) Ac = 0.33 C) Ac = 3 D) Ac = 28 

Description : The unity gain bandwidth of an inverting amplifier is 10 MHz What would be the bandwidth if the gain is increased to 10 V/V? A) 100 MHz B) 1 MHz C) 10 MHz D) 1 kHz 

Last Answer : The unity gain bandwidth of an inverting amplifier is 10 MHz What would be the bandwidth if the gain is increased to 10 V/V? A) 100 MHz B) 1 MHz C) 10 MHz D) 1 kHz 

Description : What is the efficiency of Class-B amplifier?  A) 68.50% B) 78.50% C) 88.50% D) 98.50%

Last Answer : What is the efficiency of Class-B amplifier?  A) 68.50% B) 78.50% C) 88.50% D) 98.50%

Description : Which one of the following is another name for common-collector amplifier?  A) Source follower B) Collector follower C) Base follower D) Emitter follower

Last Answer : Which one of the following is another name for common-collector amplifier?  A) Source follower B) Collector follower C) Base follower D) Emitter follower

Description : An amplifier has input power of 2 microwatts. The power gain of the amplifier is 60 dB. The output power will be

Last Answer : An amplifier has input power of 2 microwatts. The power gain of the amplifier is 60 dB. The output power will be 2 watts

Description : A differential amplifier has a differential gain of 20,000, CMRR : 80 dB. The common mode gain is given by

Last Answer : A differential amplifier has a differential gain of 20,000, CMRR : 80 dB. The common mode gain is given by 2

Description : The gain of an ideal amplifier must be

Last Answer : The gain of an ideal amplifier must be infinity

Description : The effect of a finite gain of an operational amplifier used in an integrator is that (A) it would not integrate (B) the slope of the output will vary with time (C) the final value of the output voltage will reduce (D) there will be instability in the circuit

Last Answer : The effect of a finite gain of an operational amplifier used in an integrator is that there will be instability in the circuit

Description : What is a BJT amplifier?

Last Answer : Bilpolar Juntion transistor , this fuction is control the current

Last Answer : ADC-Amplifier interface: In most data acquisition system analog to digital converter (ADC) is interfaced with the amplifier. There are different interface architectural schemes. Operational ... . The interaction between analog to digital converter and amplifier affects the system performance.

Last Answer : Active region of BJT act as amplifier.