How did they measure the charge of electron

Click For Summary

Discussion Overview

The discussion revolves around the measurement of the electron's charge, specifically the value of 1.60217646 × 10-19 coulombs, and the definition of a coulomb and an ampere. Participants seek detailed explanations of these concepts and their interrelations.

Discussion Character

  • Conceptual clarification
  • Technical explanation
  • Homework-related

Main Points Raised

  • One participant inquires about how the charge of the electron was determined and requests detailed information about the coulomb.
  • Another participant suggests looking up the Millikan oil drop experiment as a method for measuring the charge of the electron.
  • A participant seeks clarification on the definition of a coulomb, specifically its relation to current and time.
  • Further clarification is provided regarding the definition of an ampere, linking it to mechanical units and the force between wires.

Areas of Agreement / Disagreement

The discussion does not present a consensus, as participants are exploring definitions and seeking clarifications rather than agreeing on a singular explanation.

Contextual Notes

Participants express uncertainty about the definitions of charge, coulombs, and amperes, indicating a need for foundational understanding. The discussion includes references to specific experiments and definitions but does not resolve the underlying questions.

Who May Find This Useful

This discussion may be useful for individuals interested in the fundamental concepts of electric charge, definitions of electrical units, and historical methods of measurement in physics.

Boody
Messages
4
Reaction score
0
I know that a charge is discribed in terms of coulombs. But how did they know that an electron has a charge of 1.60217646 × 10-19 coulomb ? by the way , what is a coulomb exactly ? and how did they found or discribed its quantity ? I would like the answer to be in details please . Thanks
 
Physics news on Phys.org
Look up the Millikan oil drop experiment.

A coulomb is exactly that amount of charge which results from a current of one Ampere flowing for one second.
 
you said it is " the amount of charge which results from a current of one Ampere flowing for one second " ,, what is Ampere ? and how would we find it ? ( suppose we want to calculate the charge and the magnitude of the charge is not given)
 
Welcome to PF!

Hi Boody! Welcome to PF! :smile:
Boody said:
… what is Ampere ? and how would we find it ?

The ampere (small "a" :wink:) is defined in terms of ordinary mechanical units.

From the PF Library …

the amp is that current which in a pair of wires a metre apart would produce a force between them of 2 10-7 N/m​
 


mmmm, I see

Thanks :)
 

Similar threads

Undergrad How is Coulomb's Law compatible with quantum physics?
  • · Replies 10 ·
Replies
10
Views
3K
Undergrad What is the true nature of microscopic particles when not interacting?
  • · Replies 4 ·
Replies
4
Views
2K
Undergrad The electron as a smeared charge density
  • · Replies 13 ·
Replies
13
Views
3K
Undergrad What part of physics describes what happens just outside of an electron?
  • · Replies 8 ·
Replies
8
Views
2K
Undergrad The physical components in the electron double slit experiment
  • · Replies 7 ·
Replies
7
Views
2K
High School Can someone please explain to me the motion of an electron?
  • · Replies 11 ·
Replies
11
Views
3K
Undergrad Amount of electrons in nuclei
  • · Replies 10 ·
Replies
10
Views
2K
Undergrad Measurement problem - will this work?
  • · Replies 4 ·
Replies
4
Views
3K
Undergrad How Do Radio Antennas Function in Quantum Mechanics?
  • · Replies 4 ·
Replies
4
Views
3K
Undergrad Confused about work done on charge
  • · Replies 8 ·
Replies
8
Views
2K