University Physics with Modern Physics Plus Mastering Physics with eText -- Access Card Package (14th Edition)
14th Edition
ISBN: 9780321982582
Author: Hugh D. Young, Roger A. Freedman
Publisher: PEARSON
expand_more
expand_more
format_list_bulleted
Concept explainers
Videos
Textbook Question
Chapter 27, Problem 27.48E
A dc motor with its rotor and field coils connected in series has an internal resistance of 3.2 Ω. When the motor is running at full load on a 120-V line, the emf in the rotor is 105 V. (a) What is the current drawn by the motor from the line? (b) What is the power delivered to the motor? (c) What is the mechanical power developed by the motor ?
Expert Solution & Answer
Learn your wayIncludes step-by-step video
schedule03:10
Students have asked these similar questions
A DC motor has a rotor and field coils connected in series with a resistance of 3.2 Ω. When it spins at full load on a 120 V line, the emf rotor is equal to 105 V. (a) What is the current that the motor receives from the line? (b) What is the power required for the engine? (c) What is the mechanical power developed by the engine?
A 120.0-V motor draws a current of 5.92 A when running at normal speed. The resistance of the armature wire is 0.629 a. (a)
Determine the back emf generated by the motor. (b) What is the current at the instant when the motor is just turned on and has not
begun to rotate? (c) What series resistance must be added to limit the starting current to 15.0 A?
(a) Number
i
Units
(b) Number
i
Units
(c) Number
i
Units
>
A dc motor with its rotor and field coils connected in series has an internalresistance of 2.00 Ω. When running at full load on a 120 V line, itdraws a 4.00 A current. What is the motor’s efficiency?
Chapter 27 Solutions
University Physics with Modern Physics Plus Mastering Physics with eText -- Access Card Package (14th Edition)
Ch. 27.1 - Suppose you cut off the part of the compass needle...Ch. 27.2 - Prob. 27.2TYUCh. 27.3 - Imagine moving along the axis of the...Ch. 27.4 - Prob. 27.4TYUCh. 27.5 - In Example 27.6 He+ ions with charge +e move at...Ch. 27.6 - The accompanying figure shows a top view of two...Ch. 27.7 - Figure 27.13c depicts the magnetic field lines due...Ch. 27.8 - Prob. 27.8TYUCh. 27.9 - A copper wire of square cross section is oriented...Ch. 27 - Can a charged particle move through a magnetic...
Ch. 27 - Prob. 27.2DQCh. 27 - Section 27.2 describes a procedure for finding the...Ch. 27 - The magnetic force on a moving charged particle is...Ch. 27 - A charged particle is fired into a cubical region...Ch. 27 - If the magnetic force does no work on a charged...Ch. 27 - A charged particle moves through a region of space...Ch. 27 - How might a loop of wire carrying a current be...Ch. 27 - How could the direction of a magnetic field be...Ch. 27 - A loose, floppy loop of wire is carrying current...Ch. 27 - Prob. 27.11DQCh. 27 - Each of the lettered points at the corners of the...Ch. 27 - A student claims that if lightning strikes a metal...Ch. 27 - Prob. 27.14DQCh. 27 - The magnetic force acting on a charged particle...Ch. 27 - When the polarity of the voltage applied to a dc...Ch. 27 - Prob. 27.17DQCh. 27 - Prob. 27.18DQCh. 27 - A particle with a charge of 1.24 108C is moving...Ch. 27 - A particle of mass 0.195 g carries a charge of...Ch. 27 - In a 1.25-T magnetic field directed vertically...Ch. 27 - A particle with mass 1.81 103 kg and a charge of...Ch. 27 - An electron experiences a magnetic force of...Ch. 27 - An electron moves at 1.40 106m/s through a region...Ch. 27 - CP A particle with charge 7.80 C is moving with...Ch. 27 - CP A particle with charge 5.60 nC is moving in a...Ch. 27 - A group of particles is traveling in a magnetic...Ch. 27 - A flat, square surface with side length 3.40 cm is...Ch. 27 - A circular area with a radius of 6.50 cm lies in...Ch. 27 - A horizontal rectangular surface has dimensions...Ch. 27 - An open plastic soda bottle with an opening...Ch. 27 - The magnetic field B in a certain region is 0.128...Ch. 27 - An election at point A in Fig. E27.15 has a speed...Ch. 27 - Repeat Exercise 27.15 for the case in which the...Ch. 27 - CP A 150-g ball containing 4.00 108 excess...Ch. 27 - An alpha particle (a He nucleus, containing two...Ch. 27 - In an experiment with cosmic rays, a vertical beam...Ch. 27 - BIO Cyclotrons are widely used in nuclear medicine...Ch. 27 - Prob. 27.21ECh. 27 - In a cyclotron, the orbital radius of protons with...Ch. 27 - An electron in the beam of a cathode-ray tube is...Ch. 27 - A beam of protons traveling at 1.20 km/s enters a...Ch. 27 - A proton (q = 1.60 1019 C, m = 1.67 1027 kg)...Ch. 27 - A singly charged ion of 7Li (an isotope of...Ch. 27 - Crossed E and B Fields. A particle with initial...Ch. 27 - (a) What is the speed of a beam of electrons when...Ch. 27 - A 150-V battery is connected across two parallel...Ch. 27 - A singly ionized (one electron removed) 40K atom...Ch. 27 - Singly ionized (one electron removed) atoms are...Ch. 27 - In the Bainbridge mass spectrometer (see Fig....Ch. 27 - Prob. 27.33ECh. 27 - A straight, 2.5-m wire carries a typical household...Ch. 27 - A long wire carrying 4.50 A of current makes two...Ch. 27 - An electromagnet produces a magnetic field of...Ch. 27 - A thin, 50.0-cm-long metal bar with mass 750 g...Ch. 27 - A straight, vertical wire carries a current of...Ch. 27 - Prob. 27.39ECh. 27 - The plane of a 5.0 cm X 8.0 cm rectangular loop of...Ch. 27 - The 20.0 cm 35.0 cm rectangular circuit shown in...Ch. 27 - A rectangular coil of wire, 22.0 cm by 35.0 cm and...Ch. 27 - CP A uniform rectangular coil of total mass 212 g...Ch. 27 - Both circular coils A and B (Fig. E27.44) have...Ch. 27 - Prob. 27.45ECh. 27 - Prob. 27.46ECh. 27 - Prob. 27.47ECh. 27 - A dc motor with its rotor and field coils...Ch. 27 - Figure E27.49 shows a portion of a silver ribbon...Ch. 27 - Prob. 27.50ECh. 27 - When a particle of charge q 0 moves with a...Ch. 27 - A particle with charge 7.26 108C is moving in a...Ch. 27 - Prob. 27.53PCh. 27 - Prob. 27.54PCh. 27 - Prob. 27.55PCh. 27 - The magnetic poles of a small cyclotron produce a...Ch. 27 - A particle with negative charge q and mass m =...Ch. 27 - A particle of charge q 0 is moving at speed in...Ch. 27 - Suppose the electric field between the plates in...Ch. 27 - Mass Spectrograph. A mass spectrograph is used to...Ch. 27 - A straight piece of conducting wire with mass M...Ch. 27 - CP A 2.60-N metal bar, 0.850 m long and having a...Ch. 27 - BIO Determining Diet. One method for determining...Ch. 27 - CP A plastic circular loop has radius R, and a...Ch. 27 - Prob. 27.65PCh. 27 - A wire 25.0 cm long lies along the z-axis and...Ch. 27 - A long wire carrying 6.50 A of current makes two...Ch. 27 - The rectangular loop shown in Fig. P27.68 is...Ch. 27 - Prob. 27.69PCh. 27 - Prob. 27.70PCh. 27 - The loop of wire shown in Fig. P27.71 forms a...Ch. 27 - CP A uniform bar has mass 0.0120 kg and is 30.0 cm...Ch. 27 - CALC A Voice Coil. It was shown in Section 27.7...Ch. 27 - Prob. 27.74PCh. 27 - CALC Force on a Current Loop in a Nonuniform...Ch. 27 - Quark Model of the Neutron. The neutron is a...Ch. 27 - A circular loop of wire with area A lies in the...Ch. 27 - DATA You are using a type of mass spectrometer to...Ch. 27 - Prob. 27.79PCh. 27 - DATA You are a technician testing the operation of...Ch. 27 - A particle with charge 2.15 C and mass 3.20 1011...Ch. 27 - Prob. 27.82CPCh. 27 - If a proton is exposed to an external magnetic...Ch. 27 - BIO MAGNETIC FIELDS AND MRI. Magnetic resonance...Ch. 27 - The large magnetic fields used in MRI can produce...
Additional Science Textbook Solutions
Find more solutions based on key concepts
17. A speed skater moving to the left across frictionless ice at 8.0 m/s hits a 5.0-m-wide patch of rough ice....
Physics for Scientists and Engineers: A Strategic Approach with Modern Physics (4th Edition)
Look up the enthalpy of formation of atomic hydrogen in the back of this book. This is the enthalpy change when...
An Introduction to Thermal Physics
Based on recent data, describe the general nature of Titan and discuss its prospects for life.
Life in the Universe (4th Edition)
14. A beaker of water rests on a scale. A metal ball is then lowered into the beaker using a string tied to the...
College Physics: A Strategic Approach (3rd Edition)
Number of neutrons in an atom of phosphorus-31.
Glencoe Physical Science 2012 Student Edition (Glencoe Science) (McGraw-Hill Education)
Knowledge Booster
Learn more about
Need a deep-dive on the concept behind this application? Look no further. Learn more about this topic, physics and related others by exploring similar questions and additional content below.Similar questions
- A motor in normal operation carries a direct current of 0.850 A when connected to a 120-V power supply. The resistance of the motor windings is 11.8 . While in normal operation, (a) what is the back emf generated by the motor? (b) At what rate is internal energy produced in the windings? (c) What If? Suppose a malfunction slops the motor shaft from rotating. At what rate will internal energy be produced in the windings in this case? (Most motors have a thermal switch that will turn off the motor to prevent overheating when this stalling occurs.)arrow_forwardA 120 V series-wound dc motor has a field resistance of 86 and an armature resistance of 10. When operating at full speed, a back emf of 80 V is generated. A 120 V series-wound de motor has a field resistance of 85 2 and an armature resistance of 10 2 When operating at full speed, a back emf of 80 V is generated. (a) What is the total resistance of the motor? 2 (b) What is the starting cument?arrow_forwardJohn is using a cordless electric weed trimmer with a dc motor to cut the long weeds in his backyard. During normal operation the trimmer generates a back emf of 16 V when it is connected to an emf of 24 V dc. The total electrical resistance of the motor is 8.0 Ω. (a) How much current flows through the motor when it is running smoothly? (b) Suddenly the string of the trimmer gets wrapped around a pole in the ground and the motor quits spinning. What is the current through the motor now? (c) How does the amount of heat dissipated in the motor during normal operation compare to the amount of heat dissipated when the motor is stuck? Calculate the ratio of the two amounts.arrow_forward
- A dc motor with its rotor and field coils connected in series has an internalresistance of 2.00 Ω. When running at full load on a 120 V line, itdraws a 4.00 A current. What is the power delivered to the motor?arrow_forwardA 120.0-V motor draws a current of 6.64 A when running at normal speed. The resistance of the armature wire is 0.651 . (a) Determine the back emf generated by the motor. (b) What is the current at the instant when the motor is just turned on and has not begun to rotate? (c) What series resistance must be added to limit the starting current to 15.0 A?arrow_forwardA motor has coils with a resistance of 25 Ω and operates from a voltage of 241 V. When the motor is operating at its maximum speed, the back emf is 140 V (a) Find the current in the coils when the motor is first turned on. ?A (b) Find the current in the coils when the motor has reached maximum speed. ?A (c) If the current in the motor were 5.0 A at some instant, what is the back emf at that time? ?varrow_forward
- A dc motor with its rotor and field coils connected in series has an internalresistance of 2.00 Ω. When running at full load on a 120 V line, itdraws a 4.00 A current. What is the rate of dissipation of energy in the internal resistance?arrow_forwardA motor has coils with a resistance of 26 2 and operates from a voltage of 237 V. When the motor is operating at its maximum speed, the back emf is 147 V. (a) Find the current in the coils when the motor is first turned on. A (b) Find the current in the coils when the motor has reached maximum speed. A (c) If the current in the motor were 5.0 A at some instant, what is the back emf at that time? Varrow_forwardA motor has coils with resistance of 20 Ω and operates from a voltage of 120 V. When the motor is operating at its maximum speed, the back emf is 100 V. Find the current in the coils (a) when the motor is just turned on and (b) when the motor has reached its maximum speed.arrow_forward
- The bolt of lightning depicted in the figure passes 200 m from a 90 turn coil oriented as shown. If the current in the lightning bolt falls from 7.00x106 A to zero in 9.9 μs, (b) what is the average voltage induced in the coil?arrow_forwardChapter 20: Problem 12: The hydroelectric generators at the Hoover Dam can produce a maximum current of 8.00 × 10³ A at 250 kV. a) What is the maximum power output of the generators, in watts? b) The water that powers the generators enters and leaves the system at a low speed (thus we can neglect its change of kinetic energy) and loses 160 m of altitude during the process. What is the water flow required, in cubic meters per second, to produce this power, assuming 77 % efficiency?arrow_forwardA motor contains a coil with a total resistance of 10 Ω and is supplied by a voltage of 120 V. When the motor is running at its maximum speed, the back emf is 70 V. (A) Find the current in the coil at the instant the motor is turned on. (B) Find the current in the coil when the motor has reached maximum speed.arrow_forward
arrow_back_ios
SEE MORE QUESTIONS
arrow_forward_ios
Recommended textbooks for you
Physics for Scientists and Engineers, Technology ...PhysicsISBN:9781305116399Author:Raymond A. Serway, John W. JewettPublisher:Cengage Learning
Principles of Physics: A Calculus-Based TextPhysicsISBN:9781133104261Author:Raymond A. Serway, John W. JewettPublisher:Cengage Learning
Glencoe Physics: Principles and Problems, Student...PhysicsISBN:9780078807213Author:Paul W. ZitzewitzPublisher:Glencoe/McGraw-Hill
Physics for Scientists and Engineers, Technology ...
Physics
ISBN:9781305116399
Author:Raymond A. Serway, John W. Jewett
Publisher:Cengage Learning
Principles of Physics: A Calculus-Based Text
Physics
ISBN:9781133104261
Author:Raymond A. Serway, John W. Jewett
Publisher:Cengage Learning
Glencoe Physics: Principles and Problems, Student...
Physics
ISBN:9780078807213
Author:Paul W. Zitzewitz
Publisher:Glencoe/McGraw-Hill
Magnets and Magnetic Fields; Author: Professor Dave explains;https://www.youtube.com/watch?v=IgtIdttfGVw;License: Standard YouTube License, CC-BY