The rotor of a 4-pole, 50 Hz, 3-phase slip-ring induction motor has a resistance of 0.252/phase and runs at 1440 r.p.m. on full-load. Calculate the external resistance per phase which must be added to lower the speed to 1200 r.p.m. , the torque remaining constant in both cases. Ans[ 12]

The rotor of a 4-pole, 50 Hz, 3-phase slip-ring induction motor has a resistance of 0.252/phase and runs at 1440 r.p.m. on full-load. Calculate the external resistance per phase which must be added to lower the speed to 1200 r.p.m. , the torque remaining constant in both cases. Ans[ 12]

Delmar's Standard Textbook Of Electricity

7th Edition

ISBN:9781337900348

Author:Stephen L. Herman

Publisher:Stephen L. Herman

Chapter35: Harmonics 916

Section: Chapter Questions

Problem 3RQ: Would a positive-rotating harmonic or a negative-rotating harmonic be more harmful to an induction...

See similar textbooks

Related questions

Q: QI: A BPCM system is used to transmit signal of 512 levels, the input signal works in the range…

A: We need to find data rate and signal to noise ratio.

Q: (c) y[n] – 2y[n – 1] + 3y[n – 2] - 5y[n – 3] 4.xn] – 2n (d) yn = 0.25(xn + xn - 1 + x[n 11 21-15xln…

Q: rectangular form

Q: R =1 kli R= 56 kn Ba = 100 Vec = 15 L e = 5V

Q: 1: Theory 1.1 Describe briefly a sinusoidal signal and ALL its properties. Give example with…

Q: 3. Solve the given circuit to find the current through the 15 - 52 resistor using Thevenin s I 200…

A: Circuit is given as:

Q: Find ir in the circuit in (Figure 1). Suppose R = 8 kN. The op amp in the circuit is ideal. Express…

A: In this question, We need to determine the Value of current iL as shown in the circuit. We are…

Q: Use node analysis to determine node voltages and branch currents in the image below.

A: In this question we need to find a node voltages and branch currents in the image below.

Q: A Phase modulator has a carrier signal of ec = 100 cos [2t(735 x 103)t] and phase deviation constant…

A: According to the signal, for the given phase modulation, we need to find a. The effective voltage of…

Q: e) For the amplifiers shown in the figure below, write and explain the formula for the V1 and Vout…

A: This question belongs to analog electronics. It is based on the concept of inverting op amp . It is…

Q: (CLO-2] A given sequential circuit made up of one positive-edge triggered J-K flip-flop. The circuit…

Q: Find the z parameters of the two-port network :

A: In this question, We need to find the Z parameters of two port network.

Q: Solve the current using superposition theorem and solve for the individual currents of each…

A: To apply superposition we will activate one source at a time. (a) Due to 5∠30°: Short circuit the…

Q: Q5 The charge of the condenser q() = [ 163) I(x)dx %3D is the rate of change of the current I.…

Q: 3.12. Each of the two sequences x[n] and x2[n] has a period N = 4, and the correspond- ing Fourier…

Q: In the given circuit below, determine the current flowing through each resistors using; Kirchhoff's…

A: This question belongs to circuit theory . It is based on the concept of mesh analysis and…

Q: V D8.1. Given the following values for P1, P2, and IAL1, calculate AH2: (a) P1(0, 0, 2), P2(4, 2,…

Q: 80 2 I, j60 2 20 Ω ww ell 100/120° V -j40 2 -j40 2 60 30° V

Q: 5. Using the circuit below, determine the power taken by R3. R; 150 2 ww 500 2 R2 1 k2 R, R4 450 2…

Q: Determine the Thevenin's and Norton's uivalent circuits at terminals a-b. 12V ミuう (2V びり: 12V + (+)

Q: $ 2202 Find: Is , Ic, Is 10 V 5V VBE , VCE , VcB Pacz175

A: In this question , we will find emiiter ,base ans collector current and unknown voltages....

Q: 3) Is it possible to directly subtract two power measurements expressed in dBm? Explain or prove…

A: (3) 1. In a strict sense, one can't directly perform addition or subtraction operations on dBm…

Q: = 15 V, V = 6 V termine the minimum voltage. -11 V -15 V -21 V 0-9V

Q: .For the series RLC circuit shown below, find the resonant frequency wo = 2nfo. Also obtain the…

Q: Calculate Ij and I2 in the two-port of 2Ω I I, Z11 = 6 Q Z12 = -j4 Q Z21 =-j4 2 Z22 = 8 Q 2/30° V V…

A: This question belongs to circuit theory . It is based on the concept of z parameters in two port…

Q: 4. If the diode is open in the circuit, the load voltage is? 5. If the resistor is ungrounded in the…

A: We are authorized to answer three subparts at a time, since you have not mentioned which part you…

Q: 4. Determine the current passing through the 7K ohm resistor 1k 2k 5V 3k -7k

Q: Find the z parameters of the two-port network in Fig. 18.9. Answer: z11 = 14, z12 = Z21 = Z22 6 2.…

Q: Q1)A 3 phase induction motor is wound for 6 poles and is supplied from 50-Hz system. Calculate 1.…

Q: Make a schematic diagram of a light saber

A: It is asked to make schematic of a light saber.

Q: flab,code):1I(0, 3,6,9,1!,19,20,24,25, 26,27,28, 29, 30) ΠD (,.a,12,13)

Q: Solve for the electric network 120 12V 200 10V ww- 150 find the values of each current across each…

A: We need to find out current through each resistor .

Q: LM 117 VIN-28V - VIN Vour VOUT R2 is half as much as R1 and Vref is 2v. ADJ R1 240 Vref ladi 11 C1…

A: We need to find out current for given circuit

Q: What is the conductivity of AWG #32 tungsten wire with a resistance of 0.0172 2/cm? The diameter of…

Q: 1. When gre the p-n junctions of the n-channel FET blocked?

A: Note: We are authorized to answer the first question since the exact one wasn’t specified. Please…

Q: 3) Point charge of 6x10-6C and 9x10-6C are located at points M(1, 2, 3) and N(2, 4, 6),…

A: Since you have posted the multiple questions so we are supposed to answer the 1st one.

Q: 7. If line frequency is 60 Hz, what is the output frequency of a bridge rectifier? 8. If the load…

A: As per the guidelines given to us, we can only provide the solution of first question in multiple…

Q: For the following BJT amplifier circuit whose V, = 40 mV, Rsource = 1.2 k2, A,NL = 320, and V, =…

A: We need to find out input current for given circuit

Q: 2. In the circuit shown in Figure 2, solve the given circuit to find the current through 3 Q…

Q: At extremely high frequency then the imaginary terms in Eq. 4. dominate – i.e. we can neglect the…

A: In this case, the given expression needs to be explained.

Q: A cast steel toroid has an average diameter of 6 in and a circular section whose area is 0.48 sq.…

A: Given, Average diameter, D=6 in=0.1524 m Cross sectional area, A=0.48 in2=3.1×10-4 m2 Turns in coil,…

Q: The Fourier Series

Q: Q2) A d.c. shunt motor has the armature and field resistance is 0.012 and 50 Q, when the input power…

A: This question belongs to electrical machine . It is based on the concept of armature power developed…

Q: 1. Based on the circuit, where v,(t) is the input, and v, (t) is the output. Answer the following…

Q: Use mesh-current analysis to find the branch currents indicated in the network shown below. I1 の0°v…

Q: Use Thevenin's theorem to find Vo in the network. 2Ix J1Ω 1Ω -ji27 12 220°A 12 12 65°v 420°v ll

Q: 4. For the circuit shown below answer the following. (a) Determine the Boolean expression for the…

A: We need to find out Boolean expression and Design by using of nand gate

Q: LM 117 VIN-28V VIN VOUT VOUT R2 is half as much as R1 and Vref is 2V. ADJ Vref R1 240 ladj 11 C2…

A: “Since you have asked multiple questions, we will solve the first question for you. If you want any…

Q: A hypothetical isotropic antenna is radiating in free-space. At a distance of 100 m from the…

A: We will find out power density and power radiated

Q: 5. Find the current through the 5 - Q resistor shown in Figure 5 using the source transformation for…

A: Voltage source in series with a resistor can be replaced with a current source in parallel to a…

Concept explainers

Three Phase Induction Motor

The induction motor is an electric motor that runs on AC (alternating current) and it is of two type single phase motor that work on single-phase power supply and three-phase motor that work on three-phase power supply.

Question

The rotor of a 4-pole, 50 Hz, 3-phase slip-ring induction motor has a resistance of 0.252/phase
and runs at 1440 r.p.m. on full-load. Calculate the external resistance per phase which must be
added to lower the speed to 1200 r.p.m. , the torque remaining constant in both cases. Ans[ 12]

Expert Solution

This question has been solved!

Explore an expertly crafted, step-by-step solution for a thorough understanding of key concepts.

SEE SOLUTION Check out a sample Q&A here

Step 1

VIEW

Step 2

VIEW

Step 3

VIEW

Step by step

Solved in 3 steps with 2 images

SEE SOLUTION Check out a sample Q&A here

Knowledge Booster

Learn more about

Need a deep-dive on the concept behind this application? Look no further. Learn more about this topic, electrical-engineering and related others by exploring similar questions and additional content below.

Similar questions

Would a positive-rotating harmonic or a negative-rotating harmonic be more harmful to an induction motor? Explain your answer.
A 3-phase, 50-Hz induction motor with its rotor star-connected gives 500-V(r.m.s.) at standstill between the slip-rings on open-circuit. Calculate the current and power factor at standstill when the rotor winding is joined to a star-connected external circuit, each phase of which has a resistance of 10 Q and an inductance of 0.04 H. The resistance per phase of the winding is 0.2 Q and its inductance is 0.04 H. Also, calculate the current and power factor when the slip-rings are short-circuited and the motor is running with a slip of 5 per cent. Assume flux remain constant.
A 3-phase, 50-Hz induction motor with its rotor star-connected gives 500 V (r.m.s.) at standstill between the slip-rings on open-circuit. Calculate the current and power factor at standstill when the rotor winding is joined to a star-connected external circuit, each phase of which has a resistance of 10 Q and an inductance of 0.04 H. The resistance per phase of the rotor winding is 0.2 N and its inductance is 0.04 H. 4. Also, calculate the current and power factor when the slip-rings are short-circuited and the motor is running with a slip of 5 per cent. Assume the flux to remain constant. Identify it`s given and solve it
3.An induction motor has a rotor resistance and reactance at standstill of 0.1 ohm and 3.5 ohm respectively. At standstill the voltage induced to the rotor is 60volts per phase. If the slip is 5%, determine the rotor current
8. A 3-phase induction motor is running at 2% slip. If the input to rotor is 1000 W, then mechanical power developed by the motor is ............ (i) 20 W (iii) 500 W (ii) 980 W (iv) 200 W
1. The operation of Commutator in DC Motor is * O a) to convert dc to ac O b) to convert ac to dc O c) to convert fixed dc to variable dc O reverse the current direction in the rotating windings each half turn
A 3-0, 50-Hz induction motor with its rotor star-connected gives 500 V (r.m.s.) at standstill between slip-rings on open circuit. Calculate the current and power factor in each phase of the rotor windings at standstill when joined to a star-connected circuit, each limb of which has a resistance of 10 Q and an inductance of 0.03 H. The resistance per phase of the rotor windings is 0.2 Q and inductance 0.03 H. Calculate also the current and power factor in each rotor phase when the rings are short- circuited and the motor is running with a slip of 4 per cent. [13.6 A, 0.48; 27.0 A, 0.47] (London University) A 4-pole, 50-Hz, 3-phase induction motor has a slip-ring rotor with a resistance and standstill reactance of 0.04 2 and 0.2 2 per phase respectively. Find the amount of resistance to be inserted in each rotor phase to obtain full-load torque at starting. What will be the approximate power factor in the rotor at this instant ? The slip at full-load is 3 per cent. [0.084 2, 0.516 p.f.]…
An 8 pole, 50 Hz slip ring induction motor runs at a slip of 2.67% on full load. The rotor resistance per phase of the winding is 0.2 ohm. What external resistance per phase must be added in the rotor circuit so that the motor now runs ate a slip of 17.33% such that the torque remains same in both the cases. (Ans: 1.1 ohm)
6- Which of the following supply is given to the rotor winding of 3-Phase Induction Motor: a) DC Supply b) AC Supply c) No Supply d) Pulsating Supply 7- 3-Phase Induction Motor will have Starting Torque and Starting Current a) High, High b) Low, Low. c) High, Low d) Low, High 8- Which of the following method is used for controlling the speed of an induction motor: a) Changing number of stator poles b) Supply voltage control c) Frequency control d) All the options are correct 9- Which of the following method cannot be used for starting of 3-Phase Squirrel Induction Motor: a) Star-Delta Starting b) Line resistor startling c) transformer Starter d) Rotor Resistance Starting 10- The rotor of a stepper motor has no: a) windings b) commutator c) brushes d) all of the above
The efficiency of 3-ph induction motor. at (Is=4.5A, T=13 N.m, N=1333 rpm, Pph=864 watt ) is
A four-pole induction motor drives a load at 2478 rpm. This is to be accomplished by using an electronic converter to convert a 400-V dc source into a set of three-phase ac voltages. Part A Find the frequency required for the ac voltages assuming that the slip is 4 percent. The load requires 2 hp. Express your answer to three significant figures and include the appropriate units. f= Submit Part B Value I = HA Request Answer Submit If the dc-to-ac converter has a power efficiency of 90 percent and the motor has a power efficiency of 80 percent, estimate the current taken from the dc source. Express your answer to three significant figures and include the appropriate units. HÅ Value Units Request Answer ? Units ?
If a 4-pole induction motor has a synchro- nous speed of 1500 r.p.m., then, supply fre- quency is (1) 50 Hz 60 Hz (iii) (ii) 25 Hz (iv) none of the above