1. Sam and Soul

2.  Solenoid is a long straight coil of wire that can be used to generate a nearly uniform magnetic field which is similar to the bar magnet.  http://www.stmary.ws/highschool/physics/home/no tes/electricity/magnetism/Solenoid/AlarmHowWorks.html http://www.stmary.ws/highschool/physics/home/no tes/electricity/magnetism/Solenoid/AlarmHowWorks.html

3.  B= Magnetic field  µ= permeability (the measure of the ability of a material to support the formation of a magnetic field within itself)  n= turn density (the number of turns per unit length)  I= current

4.  The solenoid can be enhanced with adding an iron core in the uniform magnetic field.  Compared to the air core, a iron core has the effect of multiplying the magnetic field about a hundred times greater.

5.  Directly proportional to the number of turns in the solenoid  Directly proportional to the strength of current in the solenoid  Dependent on the nature of core material used in making the solenoid.

6. 1. What are the four ways to increase the magnetic field? 2. Why is iron used to enhance a solenoid?

7. 1. Iron core, increase current, use higher permeability metal, and increase turn density. 2. Iron is used because it increases the magnetic force, while air cores do not. Iron boosts the strength of a solenoid better than most metals, and also helps the coil keep its shape.