DAILY QUESTION April 7, What is a solenoid?

WARNING!!!  This Chapter will have an open note test… Get those pencils ready!

FORMAT OF NOTE PACKETS  Define the section vocabulary  Section Notes  Quiz over the section (write out the questions and the answers)  Section Review Questions (write out the questions and the answers)

Agenda4/7/09  Daily Question  Define Ch 17 Section 2 Vocabulary  Ch 17 Sect 2 Notes  Brain Pop – “Electromagnets”  Quiz over Section 2 Assignments: 1. Page 575 #1-4

 Electric currents produce magnetic fields

Right-hand Rule  If you imagine holding the wire in your right hand with your thumb pointing in the direction of the positive current, the direction your fingers would curl is in the direction of the magnetic field. Figure 7 on page 571

A strong magnetic field  Can be produced by wrapping the wire into a coil Solenoid- a coil of wire with an electric current in it  Has a strong magnetic field  Has a north and south pole  More loops or more current = stronger

Electromagnets  A coil that has a soft iron core and that acts as a magnet when an electric current is in the coil

The movement of charges causes all magnetism  Magnetic atoms rotate to align with magnetic fields of nearby atoms Domains – areas where atoms point in the same direction

Electromagnetic Devices  Galvonmeters Detects current, or the movement of charges in a circuit Consists of a coil of insulated wire wrapped around an iron core that can rotate between the poles of a permanent magnet

Electromagnetic Devices  Electric motors A device that converts electrical energy into mechanical energy

Section 2 Quiz – Answer the following. 1.What is produced around a current- carrying wire? 2.What is a solenoid? 3.What is an electromagnet? 4.What type of electromagnetic device uses the magnetic field to measure current? 5.What type of energy conversion occurs in an electric motor?

Assignment:  Complete the Section 2 Review Questions: #1- 4 on page 575