State applications of single phase AC motors. 

1 Answer

Answer :

Water pumps

 ceiling fan & air conditioners.

 lathe machine

 washing machines.

 Blowers

 Mixers & grinders

 Compressors

 Conveyers

 Refrigerators.

Related questions

Description : Describe the construction and working principle of single phase AC motor.

Last Answer : construction and working principle of single phase AC motor : Single phase induction motors have a phase distributed winding on the stator and a squirrel cage short-circuited winding on the rotor. ... is the basic working principle of induction motor of either type, single phase of 3 phase.

Description : Describe the operation of inductor with sinusoidal AC voltage as input. Draw waveform for voltage across and current through the inductor. Draw its phasor representation.

Last Answer : An alternating voltage is applied to a purely inductive coil, a back e.m.f. is produced due to self-inductance of the coil. The back e.m.f. at every step, opposes the rise of fall of current through the coil ... drop, the applied voltage has to overcome this self induced e.m.f. only.

Description : Define RMS value and Average value of AC waveform.

Last Answer : 1. RMS value:- For an alternating current, the RMS value is defined as that value of steady current (DC) which produces the same heat or power as is produced by the alternating current during the ... by averaging all the instantaneous values of its wave over a period of half cycle. Iav=0.637 Imax

Description : Draw the construction of BJT (NPN) and explain its working principle. State and explain different operating regions.

Last Answer : Construction of BJT (NPN): Working of NPN Transistor : The circuit diagram of the NPN transistor is shown in the figure below. The forward biased is applied across the emitter-base ... Zero with input current is Zero transistor in cut off. In this region transistor act as open switch

Description : Define filter. State its types. Draw any one filter with input and output waveform.

Last Answer : Defination : Filter is a circuit which remove or filtered out the AC component (ripple) Types of filter 1. Shunt Capacitor filter (C filter) 2. Series Inductor filter (L filter) 3. LC filter 4. filter (CLC filter) Shunt Capacitor filter (C filter) OR Waveforms:

Description : State the need for filter circuits in power supply.

Last Answer : Ripple must be kept away from the load and it should be removed from the rectified output. Therefore , there is a necessity of filter circuit for removing i.e. smoothing or filtering the ripple and allowing the (pure or steady) d.c. voltage to reach the load.

Description : State the different types of transformers. Describe the construction and general principle of transformer.

Last Answer : Different types of transformer are core type shell type Berry type Construction of transformer: OR Shell Type construction can be consider for diagram Transformer ... is based on the principle of mutual induction between two circuits linked by a common magnetic field. 

Description : Draw and describe power triangle. State its significance.

Last Answer :  Power Triangle:   OR   Power Triangle is a right angled triangle whose sides represent the active, reactive and apparent power. It is obtained by multiplying the circuit current I ... loss due to different load. This is very important for designing the energy efficient electrical system. 

Description : Write the Emf equation of transformer. State the meaning of each term in it. 

Last Answer : EMF equation of Transformer:- E1 = 4.44 f ØmN1 OR E1 = 4.44 f BmAN1 E2 = 4.44 f ØmN2 OR E2 = 4.44 f Bm AN2 Let, E1 = Primary emf E2 = Secondary emf N1= Number of turns in the primary N2 ... flux in core (wb) Bm= Flux density (wb/m2 /Tesla) A= Area of cross section of core m2 F = Frequency 

Description : State Lenz’s law.

Last Answer : Lenz’s Law: It states that the direction of electromagnetically induced emf is such that it always opposes the main cause of its production. Or It is expressed by equation E = - N (dΦ/dt) volts Where – sign indicate the direction EMF is induced opposite to rate of change of flux. 

Description : Draw the diagram of transistor operating regions

Last Answer : diagram of transistor operating regions

Description : Explain the working of Half wave rectifier with suitable diagram

Last Answer : The half-wave rectifier circuit using a semiconductor diode (D) with a load resistance RL but no smoothing filter is given in the figure. The diode is connected in series with the secondary of the ... . Since only half-cycles of the input wave are used, it is called a half wave rectifier. 

Description : Explain with neat diagram how transistor can be used as a switch.

Last Answer : In Bipolar Transistor as a Switch the biasing of the transistor, either NPN or PNP is arranged to operate the transistor at both sides of the I-V characteristics curves. The areas ... possible and maximum current flowing through the transistor. Therefore the transistor is switched Fully-ON .

Description : Explain Zener diode as voltage regulator. 

Last Answer : Zener Diodes can be used to produce a stabilised voltage output with low ripple under varying load current conditions. By passing a small current through the diode from a voltage source, via a ... across the load in spite of variations in the input voltage or changes in the load current. 

Description : Explain the construction details of LED

Last Answer : The construction of LED differs from normal standard diode in many aspects. As shown in the figure the p-n junction of the LED bulb is enclosed by a transparent, hard plastic epoxy resin hemispherical- ... that much light. Due to this, the brightest light will be emitted at the top of the LED.

Description : Draw the circuit diagram and describe the working principle of full wave bridge rectifier. Draw its waveforms. 

Last Answer : During the first half cycle : During the first half cycle of the input voltage, the upper end of the transformer secondary winding is positive with respect to the lower end. Thus during the first ... , terminal D, diode D4, and terminal A back to transformer and output will positive half cycle.

Description : (i) Discuss ideal and practical voltage source (ii) Compare CB, CC and CE configuration

Last Answer : (i) Discuss ideal and practical voltage source Ideal voltage source The ideal voltage source has a constant voltage across its terminal, irrespective of the current drawn from the source. Ideal Voltage Source have zero ... to reduce. (ii) Compare CB, CC and CE configuration

Description : (i) Draw the time domain and frequency domain representation of sine wave and triangular wave. (ii) Define frequency and wavelength.

Last Answer : (i)Time domain and frequency domain representation of sine wave time domain and frequency domain representation of triangular wave.   ii) Define frequency and wavelength. Frequency ... : Wavelength can be defined as the distance between two successive crests troughs of a wave. 

Description : Describe the operation of transistor as a switch with suitable diagram.

Last Answer : In Bipolar Transistor as a Switch the biasing of the transistor, either NPN or PNP is arranged to operate the transistor at both sides of the I-V characteristics curves. The areas of operation for a transistor ... . OR Open switch Table indicating transistor as switch

Description : Compare between active and passive components.

Last Answer : active component passive component  It is a device which amplify by producing an output signal with more power in it than that of input signal It is a device which ... bidirectional function semiconductor materials are used Non-semiconductor or semiconductor material is used

Description : Define the following with respect to BJT. (i) Input resistance (ii) Output resistance

Last Answer : Input resistance: It is the ratio of small change in emitter -to-base voltage(∆VEB) to the resulting change in emitter current (∆IE) for a constant collector to base voltage(VCB) ... of BJT is ratio of voltage between output terminal and common terminal to current through output terminal. 

Description : Define α. Give the relationship between α and β.

Last Answer : Alpha (α )– It is ratio of collector current IC to emitter current IE of a transistor.

Description : Define active components. Give two examples. 

Last Answer : The component which requires power supply for its operation is called as Active component. e.g. Diode, Transistor, ICs, SCRs. OR Active Component: The component which rely on source of ... is called active component example diode , transistor, FET, and so on. They are semiconductor component

Description : Describe the construction and working principle of auto transformer.

Last Answer : An auto transformer has single winding which is used as primary and secondary winding. This winding is wound on laminated enameled magnetic core.   OR   As shown in fig. 1 the input is ... this construction we can step up the voltage. So this transformer known as step up autotransformer.  

Description : Define- (i) Current (ii) Potential difference

Last Answer : i) Current :- electric current is defined as the movement of electronics or flow of electronics inside the conducting material. Unit-ampere(A)  ii) Potential Difference: The difference between the ... the electrical circuit is known as potential difference between those points. Unit:- volt (V) 

Description : Define self induced Emf. Write equation of self induced Emf. 

Last Answer : Definition: Self-induced emf is the e.m.f induced in the coil due to the change of flux produced by linking it with its own turns. Or Self induced emf is that which is induced in a coil, due to the change in its own current or flux. Self induced emf equation. E = - N (dΦ/dt) volts

Description : Explain with circuit diagram operation of zener diode as a voltage regulator.

Last Answer : The function of a regulator is to provide a constant output voltage to a load connected in parallel with it in spite of the ripples in the supply voltage or the variation in the load ... V0 = VZ is obtained across RL, whenever the input voltage remains within a minimum and maximum voltage.

Description : (a) Define permeability. (b) Define MMF. (c) Define form factor of an alternating quantity. (d) Define frequency and time period of an alternating quality. (e) Define transformation ratio of transformer. ... and state the meaning of each term used. (g) Give two applications of single phase motors. 

Last Answer : Permeability : It is the ability of a magnetic/Non magnetic material to allow setting up of flux in it.  MMF : The magneto motive force (MMF) is the force required to setup flux in a magnetic / ... applications of single phase motors : Water pumps, ceiling fan, lathe machine

Description : What are the types of AC three phase motors?

Last Answer : Mainly there are two types. 1. Synchronous motors. a. Plain synchronous motors. b. Auto synchronous motors. 2. A-synchronous motors. a. Induction motors. 1. Single phase motors Shaded pole motor. ... universal motor. 2. 3φ commutator motors. 3φ series motor Charge motor. Compensated motor.

Description : State the types of single phase induction motors.

Last Answer : The types of single phase induction motors are: i) Resistance split phase induction motor. ii) Capacitor split phase inductor motor. a. Capacitor start induction run motor b. permanent capacitor motor c. capacitor start capacitor run induction motor iii) Shaded pole induction motor.

Description : State the classification of single phase induction motors.

Last Answer : Types of single phase induction motors: 1. Split phase induction motor. 2. Capacitor start inductor motor. 3. Capacitor start capacitor run induction motor. 4. Permanent split capacitor motor. 5. Shaded pole induction motor. 

Description : How speed control is made in single phase motors?

Last Answer : It is usually controlled by applying a variable voltage from tapped transformers, variacs, potentio meters, and tapped reactors.

Description : Which type of torque is developed in single phase motors?

Last Answer : Pulsating torque is produced.

Description : Which type of rotor is used in single phase motors?

Last Answer : Squirrel cage type

Description : Where do we require single-phase induction motors?

Last Answer : Single-phase induction motors are required where (i) 3 phase supply is not available (ii) Efficiency is of lesser importance (iii) Rating is less than one H.P. (iv) Equipment is portable

Description : Why single-phase motors are not self-starting?

Last Answer : When a 1φ supply is given to the single winding of the single phase motor, the field produced by it changes in magnitude and direction sinusoidally (pulsating flux). Such and alternating field is equivalent ... developed by the motor is equal to zero. So a single-phase motor is not self-starting.

Description : The single phasing relays are used for the protection of (a) single phase motors only (b) two phase motors only (c) two single phase motors running in parallel (d) three phase motors

Last Answer : (d) three phase motors

Description : SINGLE PHASE INDUCTION MOTORS MCQ

Last Answer : 101. After the starting winding of a single phase induction motor is disconnected from supply, it continues to run only on (a) running winding (b) rotor winding (c) field winding (d) compensating winding Ans: a ... motor is usually reduced by using (a) gearing (b) belts (c) brakes (d) chains Ans: a

Last Answer : The capacitors used in single-phase capacitor motors have no polarity marking.

Last Answer : In capacitor start single-phase motors current in the starting winding leads the voltage.

Description : The most suitable servomotor for low power applications is (A) a dc series motor. (B) a dc shunt motor. (C) an ac two-phase induction motor. (D) an ac series motor.

Last Answer : (B) a dc shunt motor.

Description : State any two applications of single phase autotransformer.

Last Answer : Applications of single phase auto transformers: 1) Give small boost to distribution cable to correct the voltage drop. 2) As auto transformer starter for induction motors. 3) As furnace supply ... . 5) In control equipment for single phase locomotives. 6) As dimmer in lighting circuits.

Description : State suitable single phase motor for following applications: (i) Table fan (ii) Mixers and Grinders

Last Answer : Application Suitable Single Phase Motor Table Fan 1) Capacitor split phase motor 2) Capacitor start capacitor run motor Mixers and Grinders 1) Universal motor 2) A.C. Series motor

Description : An advantage of DC motors over AC motors is that they _____________. A. are less expensive B. require less maintenance C. offer infinite speed variation D. all of the above

Last Answer : Answer: C

Description : Universal motors will operate on AC or DC current, and are generally found in _____________. A. portable tools B. large pump motors C. turbo electric main motors D. forced draft fans

Last Answer : Answer: A

Description : An advantage of DC motors over AC motors is that they _____________. A. are less expensive B. require less maintenance C. can be started across the line D. offer a more effective means of controlling speed

Last Answer : Answer: D

Description : The function of the autotransformers used with the starters of large AC motors is to provide _____________. A. increased voltage for starting B. increased torque for starting C. reduced voltage for starting D. speed control

Last Answer : Answer: C

Description : When troubleshooting AC motors, a portable growler can be used for locating ____________. A. open field coils B. grounded field coils C. grounded stator coils D. shorted stator coils

Last Answer : Answer: D

Description : Across-the-line starters are used with AC motors to provide _____________. A. reduced starting current B. regulated starting current C. high starting torque D. controlled starting acceleration

Last Answer : Answer: C

Description : The most common source of excitation for synchronous motors is a/an ______________. A. stepup transformer B. half-wave rectifier C. DC supply D. AC supply

Last Answer : Answer: C