Determining quantities as vectors or not

  • Context: Undergrad 
  • Thread starter Thread starter MathewsMD
  • Start date Start date
  • Tags Tags
    quantities Vectors
Click For Summary
SUMMARY

The discussion clarifies the distinction between current and current density in physics, establishing that current density is a vector quantity while current is a scalar. Current density, defined as current per cross-sectional area, incorporates both magnitude and direction, reflecting the flow of charges through a volume. In contrast, current describes the flow of charges along a line without directional components. This differentiation is not arbitrary but rooted in the mathematical definitions of these quantities.

PREREQUISITES
  • Understanding of vector and scalar quantities
  • Basic knowledge of electric current and current density
  • Familiarity with cross-sectional area in physics
  • Concept of charge movement in electromagnetism
NEXT STEPS
  • Study the mathematical definitions of vector and scalar quantities in physics
  • Explore the concept of current density in electromagnetism
  • Learn about the implications of vector quantities in electrical engineering
  • Investigate the role of dimensions in defining physical quantities
USEFUL FOR

Students of physics, electrical engineers, and anyone interested in the fundamental principles of electromagnetism and vector analysis.

MathewsMD
Messages
430
Reaction score
7
Why are some quantities vectors while others aren't? For example, we can calculate both current and current density, but why do we only consider current density to be a vector and current a scalar quantity? Is it a purely arbitrary convention or is it something more mathematically fundamental? I understand vectors like forces and displacement have directions and magnitudes associated with them, but I don't quite understand why we don't do the same thing for quantities like current? Is it to simplify equations only?
 
Mathematics news on Phys.org
Current is a vector. The difference between current and current density is the dimensions of the vector. Current density is current per cross sectional area, or number of charges moving through a volume, while current is descriptive of charges moving along a line.
 

Similar threads

How can "work" done by a force be negative?
  • · Replies 19 ·
Replies
19
Views
2K
Suvat vector versus the scalar form
  • · Replies 44 ·
2
Replies
44
Views
5K
Undergrad Do we consider a point in a coordinate system to be a scalar?
  • · Replies 2 ·
Replies
2
Views
2K
Undergrad Is there a list of root-power quantities? Or a rule of thumb?
  • · Replies 14 ·
Replies
14
Views
3K
Undergrad Why is length considered a fundamental (base) quantity?
  • · Replies 38 ·
2
Replies
38
Views
5K
Undergrad What is the role of geometry and dimensional operations?
  • · Replies 3 ·
Replies
3
Views
2K
Undergrad Quantum Hall Effect and Hall Voltage
  • · Replies 0 ·
Replies
0
Views
1K
Undergrad Solving simultaneous vector equations
  • · Replies 11 ·
Replies
11
Views
3K
High School How can scalars like voltage, impedance, etc. be added like vectors?
  • · Replies 17 ·
Replies
17
Views
3K
High School Is temperature considered a scalar quantity?
  • · Replies 35 ·
2
Replies
35
Views
6K