Lecture03 - Chapter 1,2

Lecture03 - Chapter 1,2 - EE216 C ircuit Analysis I Le...

This preview shows pages 1–5. Sign up to view the full content.

1 EE216 Circuit Analysis I Lecture # 3 – Chapter 1, 2

This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document
2 Electric Power Definition: transfer of energy per unit time Symbol: p Units: Joules per second Watts (W) p = dw/dt = (dw/dq)(dq/dt) = vi Concept: As a positive charge q moves through a drop in voltage v, it loses energy. One watt of power equals the work done in one second in moving one coulomb of charge through one volt of potential difference. 746 W = 1HP James Watt 1736 - 1819
3 Passive Sign Convention for power Power p = vi Power p = -vi If p > 0, power is being delivered to the box. If p < 0, power is being extracted from the box.

This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document
4 Positive or Negative Power? If p < 0, element is supplying or “generating” power. Positive charge flowing from lower to higher potential. How can a circuit element supply power? By converting chemical/mechanical/nuclear energy into electrical energy or releasing stored energy. If p > 0, element is absorbing or consuming power. Positive charge is flowing from higher to lower potential.
This is the end of the preview. Sign up to access the rest of the document.

This note was uploaded on 01/21/2011 for the course EE 216 taught by Professor Azharruaf during the Spring '10 term at NUCES.

Page1 / 15

Lecture03 - Chapter 1,2 - EE216 C ircuit Analysis I Le...

This preview shows document pages 1 - 5. Sign up to view the full document.

View Full Document
Ask a homework question - tutors are online