Scribe Post

Homework: Magnetism-Worksheet #1

Today in class we learned about The Right Hand rule, it tells the direction of the magnetic field around a conductor that is caring a current. The thumb pointing upwards tells the direction of the current, and the fingers which curl around tell the direction of the magnetic field. We also learned about solenoids which is wire wrapped around something often metal. Solenoids produce a magnetic field when an electrical current flows though them. Yes the Type-R does has solenoids.

Problem 63

Pieter van Musschenbroek invented the first capacitor, the leyden jar. It has a brass rod coming out of the top of an outer metal part. There is wood coating through which the brass goes through. The metal coating and wood keep the applied charge at equilibrium and do not allow it to be discharged. James Wimshurst invented the Wimshurst machine which creates strong electric charges. It has two insulated disks in the center of the machine which drive it, and as they rotate a strong charge is produced.

Problem No. 63, yo!

During the 17th and 18th centuries, several new inventions were developed to conduct tests and measure static electricity. The Leydan Jar for example, was a simple jar coated both inside and outside with foil. An electrode was then connected to a piece of foil inside the jar, which allowed electricity to be conducted. The charge then moves to the electrode with a generator. Another example of a fantastic machine was the Wimshurts machine. This machine was an electrostatic generator. In the generator there were rotating disks with metal attached to them. Though the only way it can be used is with the process of induction.

-Marcy

Chapter 24.1 #10-15

10. A magnetic field is definately present in nature because just use a magnet and you can see that they are vector quanities and exist.

11. Some magnetic forces around us are of course in magnets, by using a compass needle and magnet to see the affect it has on the compass to see the field. Also using bar magnets getting opposite poles facing each other will show the impact of magnetic fields.

12. If the currents are in the same direction, they will repel each other but if they are facing in opposite directions, the will attract because as the saying goes "opposites attract" and that is true in this case when dealing with magnets.

13. The magnetic field around a straight, current-carrying wire is numerous circular concentric circles around the wire.

14. The observable differences that will result are that the iron fillings will move opposite their original positions because they rely on the polarity of the poles of magnets and if those change, so do they.

15. a) The rod could behave this way because the poles are being moved and so the rods are probably just now attracting each other because of the switch because opposites poles attract and like ones repel.
b) The type of replacement rod that is used is a neutral rod.

63

Throughout the 17th and 18th centuries there were several new inventions developed to measure static electricity. One of these creations was the Leydan Jar. It made up of a jar coated inside and out with foil. Then an electrode was connected to the inside foil to conduct electricity. Then the charge moves to the electrode with a generator. Another invention was the Wimshurts machine. The machine is an electrostatic generator. The generator has rotating disks that carry metal on them. If the generator is used it is through the process of induction.

March 31

Equivalent resistance:
-the resistance seen by the source.
-equal to potential difference (V)/current (I)
Series Circuit:
-circuit with only one current path, with multiple drops in potential along the path
-example christmas tree lights
-current is the same in all components (I=I1=I2=I3=...)
-the sum of the potential drops is equal to the source potential (V=V1+V2+V3+...)
-the equivalent resistance is equal to the sum of the resitances and its components (Req=R1+R2+R3+...)
-ammeters must be connected in a series circuit so all current flows through it
Parallel Circuit:
-circuit with only one drop in potential with multiple paths for the current
-total current is the current supplied by the source. equal to the sum of the brance currents (I=I1+I2+I3+...)
-source potential is equal to the potential drop across each branch (V=V1=V2=V3=...)
-the reciprocal of Req is equal to the sum of the reciprocals of the resistance in each branch (1/Req=1/R1 + 1/R2 + 1/R3+...)
-voltmeters must be connected in a parallel circuit

Class Scribe Post-4/1

Class Lesson on 4/1-

Today we learned about the different meters in a circuit. Voltmeter, which is the measure of the potential difference between two distinct points on a circuit. It also has an extremely high internal resistance. We also learned about the ammeter, which is a measure of the current that passes through only one point of a circuit. In the ammeter, it has an extremely low internal resistance, differing from that of the voltmeter. The ammeter also creates an extremely small voltage drop while the voltmeter draws an extremely small current. At the beginning of the lesson we also discussed the difference between the potential difference in a parallel and series circuits through diagrams. We also did practice problems on white boards to better understand and grasp the concepts from previous lessons on circuits. The unit test was announced to be Monday on the material we learned today and the rest of the circuit stuff.

Chapter 20: #63

Throughout the 17th and 18th centuries, many breakthrough inventions were created in the field of electricity. One of these inventions was the Leyden Jar. It was constructed by taking a jar. The scientist would then coat the inside in foil and do the same for the outside of the jar. They would then connect an electrode to the inside foil in order to conduct electricity. The jar works by charging the electrode with a generator. The charge then moves into the foil. Another popular invention was the Wimshurst Machine. It was built by putting two discs spinning the opposite way. their would then be a spark gap between two metal spheres. The machine was poweered mechanically, not electrically. when the machine was cranked, it would make a spark between the two spheres.