Graph of magnetic field vs current

Lab Manuals (contained within each week)
KET simulations: http://virtuallabs.ket.org/physics/. Students will receive an e-mail from the KET Virtual Physics Labs with an invitation to enroll into the class.

PhET Interactive simulations: http://phet.colorado.edu/en/simulations/category/physics.

Expression of the experimental results is an integral part of science. The lab report should have the following format:

Cover page (10 points) - course name (PHY 132), title of the experiment, your name (prominent), section number, TA’s name, date of experiment, an abstract. An abstract (two paragraphs long) is the place where you briefly summarize the experiment and cite your main experimental results along with any associated errors and units. Write the abstract after all the other sections are completed.
The main body of the report will contain the following sections, each of which must be clearly labeled:

Objectives (5 points) - in one or two sentences describe the purpose of the lab. What physical quantities are you measuring? What physical principles/laws are you investigating?
Procedure (5 points) - this section should contain a brief description of the main steps and the significant details of the experiment.
Experimental data (15 points) - your data should be tabulated neatly in this section. Your tables should have clear headings and contain units. All the clearly labeled plots (Figure 1, etc.) produced during lab must be attached to the report. The scales on the figures should be chosen appropriately so that the data to be presented will cover most part of the graph paper.

Results (20 points) – you are required to show sample calculation of the quantities you are looking for including formulas and all derived equations used in your calculations. Provide all intermediate quantities. Show the calculation of the uncertainties using the rules of the error propagation. You may choose to type these calculations, but neatly hand write will be acceptable. Please label this page Sample Calculations and box your results. Your data sheets that contain measurements generated during the lab are not the results of the lab.
Discussion and analysis (25 points) - here you analyze the data, briefly summarize the basic idea of the experiment, and describe the measurements you made. State the key results with uncertainties and units. Interpret your graphs and discuss what trends were observed, what was the relationship of the variables in your experiment. An important part of any experimental result is a quantification of error in the result. Describe what you learned from your results. The answers to any questions posed to you in the lab packet should be answered here.
Conclusion (5 points) - Did you meet the stated objective of the lab? You will need to supply reasoning in your answers to these questions.
Overall, the lab report should to be about 5 pages long.

Each student should write his/her own laboratory report.

Duplicating reports will result in an "E" in your final grade.

All data sheets and computer printouts generated during the lab have to be labeled Fig.1, Fig. 2, and included at the end of the lab report.

Lab report without attached data sheets and/or graphs generated in the lab will automatically get a zero score

Magnetic Fields Lecture

Hello. Today we will talk about magnetism and magnetic fields. Magnetism is one of the most important fields in physics in terms of applications. It is closely linked with electricity.

Experimentally it was discovered magnetic fields affect moving charges. Moving charges produce magnetic fields. Changing magnetic fields can create electrical fields. James Clerk Maxwell first described the underlying unity of electricity and magnetism in the 19th century.

Magnets. Poles of a magnet are the ends where objects are most strongly attracted. Magnets have two poles called north and south. Similar to electric charges, like poles repel each other and unlike poles attract each other. If a permanent magnet is cut in half repeatedly, you will still have a north and south pole. Magnetic poles cannot be isolated. This differs from electric charges.

Sources of magnetic fields. The region of space around a moving charge includes a magnetic field. The charge will also be surrounded by an electric field. Magnetic field surrounds a properly magnetized magnetic material.

Magnetic fields is vector quantity symbolized by vector B. Direction is given by the direction of north pole of the compass. Needle points in that location. As an electrical field, magnetic fields also can be visualized using field lines.

Magnetic field lines. Magnetic field lines can be traced out by a compass. Iron filings can be used to show the pattern of the magnetic field lines around a permanent magnet.

Earth's magnetic field. The Earth's geographic north pole corresponds to the magnetic south pole. The Earth's geographic south pole corresponds to the magnetic north pole. The Earth's magnetic field resembles that achieved by burying a huge bar magnet deep in the Earth's interior.

The most likely source of Earth's magnetic field is believed to be electric current in a liquid part of the core since the high temperatures of the core prevent materials from retaining permanent magnetic position. The direction of the Earth's magnetic field reverses every few million years.

The angle between the horizontal and the direction of the magnetic field is called the deep angle. The compass needle would be horizontal at the equator. And the deep angle would be equal to 0 degrees. The compass needle would be pointed straight downward at the south magnetic pole. And the deep angle would be 90 degrees.

Magnetic fields. When a charged particle is moving through a magnetic field, the magnetic force acts on it. The magnitude of the magnetic force is F equals q multiply v multiply B multiply sine theta. This force has a maximum value when the charge moves perpendicularly to the magnetic field lines. This force is 0 when the charge moves along the field lines.

The SI unit of the magnetic field is called Tesla. One Tesla equals 1 Weber divided by 1 meter squared. And that equals a newton divided by coulomb multiply meter over second. And finally, equals newton divide ampere multiply meter. And one Weber is a unit of magnetic flux. The cgs unit of magnetic field is called Gauss. 1 Tesla equals 10 to 4 power Gauss. 10,000 Gauss.

Direction of magnetic force. Experiments show that the direction of magnetic force is always perpendicular to both velocity vector and the magnetic field vector. F maximum occurs when the particles move in the perpendicular to the field. And F equals 0 when the particles move in parallel to the field.

Right hand rule number 1. Point your fingers in the direction of the velocity. Curve the fingers in the direction of the magnetic field. Your thumb points in the direction of the force on a positive charge. This rule gives the direction of the force in magnetic moving charge in magnetic field. If the charge is the negative, rather than positive, the force is directed opposite that obtained from the right hand rule for the positive charge.

Force on a wire. The green cross indicates magnetic fields in direction into the page. The cross represents the tail of the arrow. Green dots would be used to represent the field directed out of the page. The dots represent the head of the arrow. In the case there is no current, there is no force.

On this slide, magnetic field vector B is into the page. On figure b, the current is up the page. The force is to the left. On figure c, the current is down the page and the force is to the right.

The total force is the sum of all the magnetic forces on all individual charges producing the current. The magnitude of the magnetic force on the current carrying wire of length l is given by F equals B times I times

l times sine theta. Theta is the angle between B vector and the direction of the current. The direction of the force is followed by the right hand rule, placing your fingers in the direction of the current instead of the velocity vector.

Generally, if the particle's velocity is not perpendicular or parallel to the magnetic field, the path followed by the particle is a spiral. The spiral part is called a helix. When the particle's velocity is perpendicular to the field vector, it will undergo circular motion.

Magnetic field of long straight wire. A current carrying wire produces a magnetic field. The compass needle deflect in directions tangent to the circle and points in the direction of the magnetic field. Direction of the field of a long straight wire.

We can use right hand rule number 2. Grasp the wire in your right hand. Point your thumb in the direction of the current. Your fingers will curve in the direction of the field.

Magnitude of the field of a long straight wire is given. The magnitude of the field at the distance r from the wire carrying a current of I is given by the formula B equals mu 0 multiply i divide 2 pi r where mu 0 is 4 pi times 10 to negative 7 Tesla multiply meter divide ampere. And it is called the permeability of the free space.

Magnetic force between two parallel conductors. The force on wire 1 is due to the current in wire 1 and the magnetic field produced by wire 2. The force per unit length is given by the formula F divide by l equals mu 0 times l1 times I2 divide 2 pi d.

Using the right hand rule, you may find that parallel conductors carrying currents in the same direction attract each other. Parallel conductors carrying currents in opposite directions repel each other. Using that force we can define magnet amperes.

The force between the parallel conductors can be used to define the amperes. If two long parallel wires in 1 meter apart carry the same current and the magnitude of the magnetic force per unit length is 2 times 10 to negative 7 newton or meter, then the current is defined to be 1 ampere in each wire.

Magnetic field of a current loop. The strength of the magnetic field produced by a wire can be enhanced by forming the wire into a loop. All of the segments, delta x, contribute to the field, increasing its strength.

Magnetic field of a current loop. The magnetic field lines for a current loop resemble those of a bar magnet. One side of the loop acts as a north pole, and the other side acts as a south pole.

The magnitude of the magnetic field at the center of a circular loop with a radius R and carrying current I is given by the formula B equals mu 0 multiplies I, current, divide 2R. With N loops in the coil, this becomes N times larger. B equals N times mu 0 multiply I divide 2R.

Magnetic field of a solenoid. The magnitude of the field inside a solenoid is constant at all points far from its ends. And the magnitude of the magnetic field is B equals mu 0 times n times I. n is the number of turns per unit length. n equals N divide l.