Homework Help is Here – Start Your Trial Now!
Science
Physics
Even if the rotor of a simple DC motor has negligible resistance, there is still a non-vanishing potential difference across its terminals when the motor is in used and current is running through it. Why is this so? (A) A motor converts electrical energy to mechanical energy so the power input P = IV, where V is the potential difference, cannot be zero. There should then be a non-vanishing V to push the charges in the rotor, for the motor to perform a meaningful amount of work. (B) The potential difference across the terminals of a motor is simply the applied voltage from a suitable source, presumably with non-zero value. (C) Positive and negative charges in a rotor are affected in different ways when it rotates upon application of electricity. Whereas negative charges cannot move, the positive charges can, causing a potential difference due to their net separation. (D) When the rotor rotates, resistance develops due to the brush system reversing the current direction in the rotor. This then leads to a potential difference by virtue of the relation V = IR, where R is the resistance, I is current, and V is the voltage. (E) Different sides of the rotor move at different velocities. This differ- ence implies different kinetic energies which then translates to a need for energy input. The energy input corresponds to a non-vanishing applied potential difference.

Even if the rotor of a simple DC motor has negligible resistance, there is still a non-vanishing potential difference across its terminals when the motor is in used and current is running through it. Why is this so? (A) A motor converts electrical energy to mechanical energy so the power input P = IV, where V is the potential difference, cannot be zero. There should then be a non-vanishing V to push the charges in the rotor, for the motor to perform a meaningful amount of work. (B) The potential difference across the terminals of a motor is simply the applied voltage from a suitable source, presumably with non-zero value. (C) Positive and negative charges in a rotor are affected in different ways when it rotates upon application of electricity. Whereas negative charges cannot move, the positive charges can, causing a potential difference due to their net separation. (D) When the rotor rotates, resistance develops due to the brush system reversing the current direction in the rotor. This then leads to a potential difference by virtue of the relation V = IR, where R is the resistance, I is current, and V is the voltage. (E) Different sides of the rotor move at different velocities. This differ- ence implies different kinetic energies which then translates to a need for energy input. The energy input corresponds to a non-vanishing applied potential difference.

College Physics
College Physics
11th Edition
ISBN:9781305952300
Author:Raymond A. Serway, Chris Vuille
Publisher:Raymond A. Serway, Chris Vuille
Chapter1: Units, Trigonometry. And Vectors
Section: Chapter Questions
Problem 1CQ: Estimate the order of magnitude of the length, in meters, of each of the following; (a) a mouse, (b)...
See similar textbooks
icon
Related questions
Question
Even if the rotor of a simple DC motor has negligible resistance, there is still a non-vanishing potential difference across its terminals when the motor is in used and current is running through it. Why is this so? (A) A motor converts electrical energy to mechanical energy so the power input P = IV, where V is the potential difference, cannot be zero. There should then be a non-vanishing V to push the charges in the rotor, for the motor to perform a meaningful amount of work. (B) The potential difference across the terminals of a motor is simply SS the applied voltage from a suitable source, presumably with non-zer value. (C) Positive and negative charges in a rotor are affected in different ways when it rotates upon application of electricity. Whereas negative charges cannot move, the positive charges can, causing a potential difference due to their net separation. (D) When the rotor rotates, resistance develops due to the brush system reversing the current direction in the rotor. This then leads to a potential difference by virtue of the relation V = IR, where R is the resistance, I is current, and V is the voltage. (E) Different sides of the rotor move at different velocities. This differ- ence implies different kinetic energies which then translates to a need for energy input. The energy input corresponds to a non-vanishing applied potential difference.
Transcribed Image Text:Even if the rotor of a simple DC motor has negligible resistance, there is still a non-vanishing potential difference across its terminals when the motor is in used and current is running through it. Why is this so? (A) A motor converts electrical energy to mechanical energy so the power input P = IV, where V is the potential difference, cannot be zero. There should then be a non-vanishing V to push the charges in the rotor, for the motor to perform a meaningful amount of work. (B) The potential difference across the terminals of a motor is simply SS the applied voltage from a suitable source, presumably with non-zer value. (C) Positive and negative charges in a rotor are affected in different ways when it rotates upon application of electricity. Whereas negative charges cannot move, the positive charges can, causing a potential difference due to their net separation. (D) When the rotor rotates, resistance develops due to the brush system reversing the current direction in the rotor. This then leads to a potential difference by virtue of the relation V = IR, where R is the resistance, I is current, and V is the voltage. (E) Different sides of the rotor move at different velocities. This differ- ence implies different kinetic energies which then translates to a need for energy input. The energy input corresponds to a non-vanishing applied potential difference.
Expert Solution
steps

Step by step

Solved in 2 steps

SEE SOLUTIONCheck out a sample Q&A here
Blurred answer
Knowledge Booster
Ferromagnetism
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
Recommended textbooks for you
College Physics
College Physics
Physics
ISBN:
9781305952300
Author:
Raymond A. Serway, Chris Vuille
Publisher:
Cengage Learning
University Physics (14th Edition)
University Physics (14th Edition)
Physics
ISBN:
9780133969290
Author:
Hugh D. Young, Roger A. Freedman
Publisher:
PEARSON
Introduction To Quantum Mechanics
Introduction To Quantum Mechanics
Physics
ISBN:
9781107189638
Author:
Griffiths, David J., Schroeter, Darrell F.
Publisher:
Cambridge University Press
Physics for Scientists and Engineers
Physics for Scientists and Engineers
Physics
ISBN:
9781337553278
Author:
Raymond A. Serway, John W. Jewett
Publisher:
Cengage Learning
Lecture- Tutorials for Introductory Astronomy
Lecture- Tutorials for Introductory Astronomy
Physics
ISBN:
9780321820464
Author:
Edward E. Prather, Tim P. Slater, Jeff P. Adams, Gina Brissenden
Publisher:
Addison-Wesley
College Physics: A Strategic Approach (4th Editio…
College Physics: A Strategic Approach (4th Editio…
Physics
ISBN:
9780134609034
Author:
Randall D. Knight (Professor Emeritus), Brian Jones, Stuart Field
Publisher:
PEARSON
SEE MORE TEXTBOOKS