MEDRADSC 1C03 Lecture Notes - Lecture 10: Ampere, Potential Energy, Electric Generator

• School: McMaster University
• Department: Medical Radiation Sciences
• Course: MEDRADSC 1C03
• Professor: Michael Farquharson

Document Summary

Resistivity (p): is a measure of how much resistance a material possesses against an electric current; intrinsic property of a material that depends on its electronic structure (how the molecules are arranged) If we apply a voltage (v) across a conductor, a current i will flow through the conductor. Property of the conducting medium that weakens the transmission of an electric current. The current i (ampere, a) is directly proportional to the potential difference v (volt, v) with resistance r (ohms, ) as the proportionality constant. Assumed that the resistance does not vary with voltage or current. Not all conducting materials follow ohm"s law. Ohmic = material that follows ohm"s law. Non-ohmic = material that does not follow ohm"s law. Linear relationship between the potential difference across a material and the current flow through an object made of that material. Semi-conductors do not follow ohm"s law (nonlinear) Resistance problems: a piece of 1. 0m wire has a resistance of 0. 19 ohms.