Element absorbing/supplying power?

  • Thread starter Thread starter phy6!
  • Start date Start date
  • Tags Tags
    Element Power
Click For Summary
SUMMARY

The discussion centers on the calculation of power in electrical circuits, specifically regarding an element with a potential of +20 V and a current of 4 A entering its negative terminal. It is established that when current flows from the negative terminal to the positive terminal, the element absorbs power, calculated as P = VI, resulting in a power absorption of -80 W. The confusion arises from the interpretation of power directionality, where a positive voltage with incoming current indicates energy absorption rather than supply. Thus, the element is indeed absorbing power from the circuit.

PREREQUISITES
  • Understanding of basic circuit theory
  • Familiarity with Ohm's Law
  • Knowledge of electrical power calculations
  • Concept of voltage polarity in circuits
NEXT STEPS
  • Study the principles of power absorption in electrical components
  • Learn about the role of voltage and current directionality in circuits
  • Explore the concept of negative power in circuit analysis
  • Investigate the differences between energy supplying and absorbing elements
USEFUL FOR

Electrical engineering students, circuit designers, and anyone interested in understanding power dynamics in electrical circuits.

phy6!
Messages
5
Reaction score
0
Hello, I am working on some basic circuit problems. I am just getting started and am having some difficulties with the wording of the problems. For example, a problem shows that 4 A of current is entering the negative terminal of an element with potential of +20 V, where I then have to calculate the power being absorbed by the element. This seems odd to me, if the potential is +20 V, then the positive terminal of the element has a higher potential compared to the negative terminal, specifically, with a magnitude of 20 V, right? So if current flows through the element in from the negative and out through the positive, aren't the electrons gaining energy as they pass through it, which means that the element is supplying energy to the circuit? Does the question imply that the element is absorbing power from its surroundings, like a battery charger or something?
 
Engineering news on Phys.org
For the problem you described, you may answer that the power absorbed is negative.
 

Similar threads

How do I properly connect a bench power supply to a pulse generator for testing?
  • · Replies 19 ·
Replies
19
Views
3K
Earth grounded, where does the current flow?
  • · Replies 19 ·
Replies
19
Views
6K
Undergrad An attempt to understand the associated variable conventions in circuits
  • · Replies 1 ·
Replies
1
Views
2K
Electrical Machines and Power Flow
  • · Replies 6 ·
Replies
6
Views
2K
High-energy LC oscillatory discharge: what kind of switch?
  • · Replies 19 ·
Replies
19
Views
2K
Fried my power supply by doing a bad thing
  • · Replies 36 ·
2
Replies
36
Views
5K
Mosfet SSR, flyback shunt/crowbar safety circuit
  • · Replies 1 ·
Replies
1
Views
2K
Why is the voltage across one resistor the same as supply?
  • · Replies 22 ·
Replies
22
Views
6K
A Physical Understanding of Kirchhoff's Laws
  • · Replies 18 ·
Replies
18
Views
4K
Undergrad Is this example incorrect in Agawal's book on electric circuits?
  • · Replies 3 ·
Replies
3
Views
2K