Electronics Fundamentals: Circuits, Devices & Applications
8th Edition
ISBN: 9780135072950
Author: Thomas L. Floyd, David Buchla
Publisher: Prentice Hall
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Question
Chapter 7, Problem 13ST
To determine
The purpose of the commutator.
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Students have asked these similar questions
Why do motors have gaps or breaks throughout the rotor and commutator?
It makes the motor cheaper since not as much material is needed.
Only some sections of the rotor will act as electromagnets, causing the
rotor to always be pushed in the same direction.
It allows some of the magnetic field to escape so that rotor doesn't get too
stressed.
It lets air into the motor to keep it cool since the electricity can make it hot.
It happens when rotors don't use enough oil, so they crack.
The electromotive force created by a direct current generator is proportional to
Flux/pole
Speed of armature
Number of poles
All of the aBove
Maximum torque is realized when an armature winding is
with the magnetic field
O at 90° O inline or at 0°
at 45° O turning
Chapter 7 Solutions
Electronics Fundamentals: Circuits, Devices & Applications
Ch. 7 - The tesla (T) and the gauss (G) are both units for...Ch. 7 - The unit for measuring magnetomotive force (mmf)...Ch. 7 - Ohm’s law for a magnetic circuit gives the...Ch. 7 - A solenoid is a form of electromagnetic switch...Ch. 7 - A hysteresis curve is a plot of flux density (B)...Ch. 7 - To produce an induced voltage in a coil, the...Ch. 7 - Prob. 7TFQCh. 7 - Prob. 8TFQCh. 7 - Prob. 9TFQCh. 7 - Prob. 10TFQ
Ch. 7 - Prob. 1STCh. 7 - Prob. 2STCh. 7 - Prob. 3STCh. 7 - Prob. 4STCh. 7 - Prob. 5STCh. 7 - Prob. 6STCh. 7 - Prob. 7STCh. 7 - The electromagnetic activation of a movable shaft...Ch. 7 - When there is current through a wire placed in a...Ch. 7 - Prob. 10STCh. 7 - Prob. 11STCh. 7 - Prob. 12STCh. 7 - Prob. 13STCh. 7 - Prob. 14STCh. 7 - Prob. 15STCh. 7 - The cross-sectional area of a magnetic field is...Ch. 7 - In a certain magnetic field the cross-sectional...Ch. 7 - Wha is the flux in a magnetic material when the...Ch. 7 - At a given location, the earth’s magnetic field...Ch. 7 - A very strong permanent magnet has a field of...Ch. 7 - Prob. 6PCh. 7 - What is the relative permeablility of a...Ch. 7 - Determine the reluctance of a material with a...Ch. 7 - What is the magnetomotive force in a 500 turn coil...Ch. 7 - Typically, when a solenoid is activated, is the...Ch. 7 - Prob. 11PCh. 7 - Explain the sequence of events in the circuit of...Ch. 7 - Prob. 13PCh. 7 - What is the magnetizing force in Problem 9 if the...Ch. 7 - How can the flux density in Figure 7-51 be changed...Ch. 7 - In Figure 7-51, determine the following if the...Ch. 7 - Determine from the hysteresis curves in Figure...Ch. 7 - According to Faraday’s law, what happens to the...Ch. 7 - The voltage induced across a certain coil is...Ch. 7 - Prob. 20PCh. 7 - A 20 cm long conductor is moving upward between...Ch. 7 - Prob. 22PCh. 7 - If a generator is 80% efficient and delivers 45 W...Ch. 7 - Prob. 24PCh. 7 - If the output voltage in Problem 24 is 14 V, what...Ch. 7 - Prob. 26PCh. 7 - Prob. 27PCh. 7 - A basic one-loop de generator is rotated at 60...Ch. 7 - Assume that another loop of wire. 90 from the...
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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 strength of the rotating magnetic field in a three phase induction motor is equal to times the flux produce ...... ....... in one of the phase windings. 1.25 1 O 1.5arrow_forwardA magnetic ring has reluctance of 1.675 × 10⁰ AT weber. The flux to be produced by the coil is 800 x 10 webers, then the AT required for the m.m.f. will bearrow_forwardmagnetic forcearrow_forward
- The voltage induced in 8 poles lamp wound generator is 120 V with armature resistance = 0.3 2. What will be the terminal voltage at a load = 3.6 A when the machine is rewound as a wave?arrow_forwardQuestion 4 To minimize the time where the voltage produced by a coil in the armature of a dc generator is zero, we minimize the A air gap B pole gap Question 5 A 6-pole dc generator with a simplex wave winding has parallel paths in its armature winding. Round your answer to 0 decimal places. Add your answerarrow_forward4-ls the residual magnetism on the generator is necessary how can you cancel these residual magnetism in D.c generatorarrow_forward
- Rotor is held to step position in a stepper motor due to Stator and rotor flux locking Rotor flux alone Stator flux alone Neither stator nor rotor magnetic fluxarrow_forwardThe frequency of rotor current in an induction motor is slip times the frequency of stator current. slip times the frequency of supply, One by slip times the frequency of stator current. One by slip times the frequency of supplyarrow_forwardMagnetic losses of a compound and shunt generator is approximately ranges from : A) 41-50% B) 10-15 % C) 20-30 % D) 35 - 409 %arrow_forward
- 4. Given the circular coil shown below, calculate the magnitude of: a. Magnetic moment b. Torque on the coil B-23T 23 r=25 inch I=45.0Aarrow_forwardRotor is held to step position in a stepper motor due to Rotor flux alone Stator and rotor flux locking O Neither stator nor rotor magnetic flux O Stator flux alonearrow_forwardA four pole machines generates 250V when operated at 1500 rpm. If the flux per pole is 1.85 x 106 maxwell, the number of armature slots is 45 and the armature winding has two parallel paths. If the speed of the generator is reduced to 1350 rpm, what would be the generated voltage. To what value of flux per pole should the excitation be adjusted if the generated voltage is to remain the same at 250Varrow_forward
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