Lab+Report+Unit+09+-+Magnetic+Fields+and+Induction

The procedure is pasted below in bold print.


 * In this experiment we utilized a Tangent Galvanometer to ascertain the magnetic field of the Earth in Orlando, Florida. Generally magnetic fields are generated anytime there is a flow of electric current. If a current flows through a circular loop of a radius R, a magnetic field is generated at the center of the loop. Using the right-hand rule, the field is perpendicular to the plane of the loop. The magnitude can be determined by using the equation:**
 * B = µ0 N I / 2R**
 * N being the number of turns in the coil, I the current flowing through the coil, and µ0 being the preset constant that equals 4π x 10-7 T∙m/A. and is the permeability of free space.**
 * In the experiment, the tangent galvanometer was composed of a circular coil and in the middle of the galvanometer was a compass used to find the direction of the magnetic field at the center. With no current, the galvanometer was moved so that it ran parallel to Earth’s magnetic field. Then it was connected to a resistor and a power supply. A number of turns would be determined, such as 15, and the current flowing through would be altered to witness the change in the needle of the compass. With this we would record a series of measurements of the angle α which the compass makes with the plane of the coil as a function of current. Three separate series would be record, current and α at 15 turns, 10 turns, and 5 turns. With these numbers we could make three graphs of current (I) vs. tanα and realize that they would plot a fairly straight line. To determine the slopes of each graph we would use linear regression. From these slopes we could calculate the Earth’s magnetic field at the point on Earth we are measuring, this magnetic field being titled Be. This is determined using the equation above altered to look like:**
 * Be = µ0 N I / 2R**
 * The radius was measured separately and recorded as 0.095 m.**

Actually, I was doing the procedure, Daniel was doing the intro. and conclusion. Andrew was doing data analysis and courtney was printing. - Ashley

Here's the graphs all clean and neat:

Here's what I used to come up with the answers along with the regression eq:

p.s. - It's pretty messy looking but it should have all the data and the graphs again (just in case).

as seen in "lab unit 9 data", the Mean I got for B is 2.47 e-5 T.

guess im doing the procedure- daniel.

Here's the finished lab. I used the lab unit 9 data instead of the less messy one because it has more info (showing my work).