Answered: The Polarization Index test determines:…

The Polarization Index test determines: a)Humidity level of the machine. b)Degree of insulation of the machine. c)Short between turns of the armature. d)Ground coils.

Delmar's Standard Textbook Of Electricity

7th Edition

ISBN:9781337900348

Author:Stephen L. Herman

Publisher:Stephen L. Herman

Chapter29: Dc Generators

Section: Chapter Questions

Problem 10RQ: What is armature reaction?

See similar textbooks

Related questions

Q: For this Assessment, design an armature winding with the following information: 1. your choice of…

A: For the design we assuming following parameters 1) winding : Lap 2) simplex 3) Number of slots : 20…

Q: 4-pole, wave-wound armature has 72 slots with two coil-sides per slot, each coil has four turns. If…

Q: Question 4 For an armature voltage of 100V, and an armature current of 10A, a separately excited dc…

Q: Draw the DC Machine and label its parts Example. Armature Winding Stator Pole Shoe/ Face Field…

A: DC Machine An electrical device that transforms electrical energy into mechanical energy is a DC…

Q: 4) A dc. ahunt machine while running as generator develops a voltage of 240 V at 1000 rp.m. on…

A: In this question we will find speed and efficiency of motor with given data....

Q: A 10 pole lap wound DC armature has a total of 200 conductors each with a current carrying capacity…

A: Given values are - Lap windingNumber of polesP=10Number of conductorsZ=200Current…

Q: Numerical Problems 1. A four-pole, lap wound DC machine is having 500 conductors on its armature and…

A: We are authorized to answer only one question at a time since you have not mentioned which question…

Q: 2. A four-pole de machine with a lap wound armature has a total of 652 armature conductors with an…

Q: -The power output of the three phase machine is greater than the single phase machine. (TRUE/FALSE)…

A: 1. Output power in three phase machine is 3 time higher then single phase machine. So given…

Q: THE ARMATURE OF A 4-POLE, 128 SLOTS SHUNT GEN. IS LAP WOUND WITH FOUR CONDUCTORS PER SLOT. THE FLUX…

A: Given,Pole, P=4Slots, S=128Conductors per slot, C=4Flux per pole, ϕ=50 mWbArmature resistance,…

Q: Calculate the required flux per pole at full load for a 50 kW, 400 V, 8 pole, 600 rpm dc shunt…

A: for shunt generator, developed armature voltage =Terminal voltage + voltage drop in armature +…

Q: 40 The armature, frame, and core of a 12-V DC control relay are made of sheet steel. The average…

A: Given data: The number of turns is: 250 The value of current is: 50 mA a) The length in meter will…

Q: b) An 8 pole, lap-wound armature has 1200 conductors and a flux pole is 0.06wb. Determine the gm.f…

A: Number of poles poles P = 8 Number of conductors Z = 1200 Flux per pole Φ = 0.06 wb Speed…

Q: Assume that a separately excited shunt de machine has a rated terminal voltage of 230 V and a rated…

A: We got an a separately excited shunt dc machine with, Terminal Voltage (Vt) = 230 V Armature current…

Q: A four-pole, lap-would DC machine has 462 conductors in the armature. The average flux per pole is…

Q: A d.c. motor connected to a 460-V supply has an armature resistance of 0.15 ohm Calculate: (a) The…

A: The detailed solution is provided below.

Q: A DC machine has 2 poles on the stator, the armature winding has 20 coils and 8 turns per coil. The…

A: Poles=2 Coils=20 Turns per coil=8 r=12.5 cm l=25 cm

Q: his according to the average magnetic flux below the poles what is the value of its density?

Q: A shunt generator has field resistance of 602 when the generator delivers 60 kw he terminal voltage…

A: The solution is given below

Q: Electrical Machines Numerical Problems 1. A four-pole, lap wound DC machine is having 500 conductors…

Q: The EMF induced in the armature of a shunt generator is 500 V. The armature resistance is 0.2 2 if…

A: Given: A shunt generator with, Induced emf in the armature, E=500 V. The armature resistance, Ra=0.2…

Q: A 900 rpm, 4 pole wave wound shunt motor takes 300 A. The flux per pole is 0.02 Wb and the armature…

A: A 900 rpm, 4 pole wave wound shunt motor takes 300 A. The flux per pole is 0.02 Wb and the armature…

Q: Q1. Calculate the voltage induced in the armature winding of a 4-pole, lap-wound DC machine having…

A: Hello since you have posted multiple questions and not specified which question to solve. We will…

Q: determine (i) Generated EMF, (ii) Total Resistance, (iii) Armature Current, (iv) Terminal Voltage.

Q: When the DC machine is running under saturation condition, then flux per pole decreases due to…

A: Ans. True

Q: A 1.5 hp Permanent magnet motor generates a voltage of 90 V when the motor runs at 2900 r/mine and…

A: The electrical energy employed as a DC motor's input source, direct current, is transformed into…

Q: the basic requirement of DC armature winding is that it must be: a) a closed one b) a lap winding c)…

A: Basic circuit on electrical machines is solved below.

Q: A 4 pole lap wound dc machine has 728 active conductors running at 1800 rpm. The flux per pole is…

Q: 1. A four-pole, lap wound DC machine is having 500 conductors on its armature and running at 1000…

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

Q: How to reduce the effect of armature reaction? a. Increase the length of the air gap b. using…

A: In this question , we will see how we reduce the effect of armature reaction...

Q: a) the terminal voltage b) the e.m.f. generated in the armature.

A: DC generator is works on faraday's laws of magnetic induction. Based on the field connection the dc…

Q: GENERAL INSTRUCTIONS: SOLVE EACH OF THE FOLLOWING PROBLEMS AND SHOW YOUR SOLUTIONS FOR EACH IΤΕΜ. 1.…

A: % voltage regulation =100× (No load terminal voltage - full load terminal voltage)/(full load…

Q: The current in a conductor on the armature of a DC motor is 300A. The flux under the poles is 850…

Q: 4. What for brushes are employed in DC generator?

A: DC Generator: The device that converts mechanical energy into electrical energy is called DC…

Concept explainers

Speed control of motor

Speed control by DC motor-speed controller is required to realize variable speed drive. Whenever a motor drives a particular load, it is called drive, and variable speed drive refers to a load requiring variable speed. All this is obtained by a DC motor speed controller.

Question

The Polarization Index test determines:

a)Humidity level of the machine.

b)Degree of insulation of the machine.

c)Short between turns of the armature.

d)Ground coils.

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 by step

Solved in 2 steps

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

the basic requirement of DC armature winding is that it must be: a) a closed one b) a lap winding c) a wave winding d) either (b) or (c)
NUMERICAL QUESTION Q1. Calculate the voltage induced in the armature winding of a 4-pole, lap-wound DC machine having 500 conductors and running at 1,000 rpm. The flux per pole is 30 mWb.? What will be induced emf if the armature is rewound for wave winding? (Ans. 250 V; 500 V) Q2. A 4-pole, wave-wound armature has 72 slots with two coil-sides per slot, each coil has four turns. If the flux per pole is 20 mWb and the armature rotates at 720 rpm, what is the induced emf across the armature? (Ans. 276.48 V) Q3. A 4-pole machine has an armature with 90 slots and 8 conductors per slot, the flux per pole is 0.05 Wb and runs at 1,200 rpm. Determine induced emf if winding is (i) lap connected and (ii) wave connected. (Ans. 720 V, 1440 V) Q 4. An 8-pole DC generator has 400 armature conductors and a useful flux of 0.05 Wb. What will be the emf generated if it is lap wound and runs at 1,500 rpm? What must be the speed at which it is to be driven to induce the same voltage if it is wave wound?…
A d.c. motor connected to a 460-V supply has an armature resistance of 0.15 ohm Calculate:(a) The value of back e.m.f. when the armature current is 120 A.(b) The value of armature current when the back e.m.f. is 447.4 V.
and the armature current 14.5 A. calculate the following: a) The number of conductors on the armature b) The value of the counter-emf at full load c) The flux per pole, in milliwebers [mWb] The following details are given: 73 mm 115 mm 20 40 Armature diameter: armature length: armature slots Image Word A 1.5 hp Permanent magnet motor generates a voltage of 90 V when the motor runs at 2900 r/min. commutator bars: turns per coil: Armature resistance at 20°C: 0.34 2. on P I Sign Extract Text I Share 1/1 More
The relationship between field current and induced armature voltage is known as open circuit characteristic of a DC machine True O False
I need the answer as soon as possible
14. How to reduce the effect of armature reaction? a. Increase the length of the air gap b. using Compensating winding c. Using interpoles d. All of the above
When the DC machine is running under saturation condition, then flux per pole decreases due to armature reaction. Select one: O True O False
a) A six-pole, lap-wound, 220 V, shunt-excited d.c. machine takes an armature current of 2.5 A when unloaded at 950 r/min. When loaded, it takes an armature current of 54 A from the supply and runs at 950 r/min. The resistance of the armature circuit is 0.18 and there are 1044 armature conductors. For the loaded condition, calculate: b) Use the information provided in Part (a) above to determine: i. The constant loss, C The output power when the machine is loaded. ii. iii. The output torque when the machine is loaded. Hint: Draw the power flow diagram.
THE ARMATURE OF A 4-POLE, 128 SLOTS SHUNT GEN. IS LAP WOUND WITH FOUR CONDUCTORS PER SLOT. THE FLUX PER POLE IS 50 mWb. THE ARMATURE AND SHUNT FIELD RESISTANCES ARE 0.04 OHM AND 50 OHMS RESPECTIVELY. DETERMINE THE SPEED OF THE MACHINE WHEN SUPPLYING 400 A AT A TERMINAL VOLTAGE OF 250V.
For the design we assuming following parameters 1) winding: LAP 2) simplex multiplicity 3) Number of slots =16 4) Number of poles = 4
Assume that a separately excited shunt de machine has a rated terminal voltage of 230 V and a rated armature current of 100 A. Its armature winding resistance, commutating winding resis- tance, and compensating winding resistance are 0.08, 0.01, and 0.00842, respectively. The resis- tance of external wires (i.e., R…) is 0.00242. Determine the following: (a) The induced armature voltage if the machine is operating as a generator at full load (b) The induced armature voltage if the machine is operating as a motor at full load