PHY 2049
Faraday’s Law
1) ABSTRACT: Relative motion between a magnetic field and a conductor are needed to create a voltage within the conductor. For current to flow the conductor must be a complete loop, if not the current will not flow.
2) THEORY: Faraday’s Law ( V = -N(Df/Dt) )
3) PROCEDURE:
A. A coil is connected to a galvanometer, completing the loop. A magnet is passed through the coil.
B. A coil is connected to a galvanometer, completing the loop. Many magnets are passed through the coil.
C. Two coils are placed end to end with an iron rod placed through them. One is connected to a galvanometer the other to a power supply. The power supply is switched on and off.
D. A large coil surrounding an iron rod is given a constant current. An aluminum ring with a slit to prevent complete current is placed over the rod.
E. A large coil surrounding an iron rod is given a constant current. A complete aluminum ring is placed over it.
F. A large coil surrounding an iron rod is given a constant current. A copper coil is placed over the rod, but is not a complete loop. The coil is then closed to complete the loop.
4) DATA AND RESULTS:
A. As the magnet passed through the coil a voltage was generated.
B. As many magnets passed through the coil a lower voltage was generated.
C. As current is supplied to the coil a voltage is generated in the iron rod. When the current is cut off there is no voltage created.
D. Current could not flow through the gapped ring so it fell straight to the bottom of the iron rod.
E. Current could flow through the complete ring so it was repelled off the iron rod upon placement.
F. The coil that is not complete falls to the bottom of the iron rod but the complete coil is also repelled off the rod due to current flow.
5) INTERPRETATION:
The experiment proved that relative motion between a magnet and conductor was able to create a voltage and that current must have a complete loop in order for it to flow, thus proving Faraday’s Law.
The perception of inequality was evident in the colonial Spanish America, man belief that women were lacked in capacity to reason as soundly as men. A normal day for European women in the new world was generally characterized by male domination, for example marriage was arranged by the fathers, women never go out except to go church, women didn’t have the right to express their opinions about politic or society issues. Subsequent to all these bad treats European women try to find different ways to escape from man domination and demonstrate their intellectual capacities, for example women used become part of a convent, write in secret their desires and disappointments, and even dress as man to discover what was the real world. On the other hand native women were not treating the same way, because their enjoyed economic importances that place them far from being man victims. However, Europeans women were very discriminated and dominated during the colonial times; but little by little women fight for their rights and become free of man domination.
idea was that electrical current flow was similar to that of heat flow, and by
In part two of the experiment, the following conditions were the same as part one,
...magnetism and whether the magnet in the first scenario is moving or not depends on which inertial frame of reference one makes his observation . If one sits stationary on top of the coil, one will see the magnet moving and an electric field is induced around him. However, if one were to sit on top of the moving magnet, then to him, the magnet is not moving and the coil is moving towards the magnet. Thus, what one will observe is that the moving coil induces a magnetic field around him. Then, is there a magnetic or electric field between the magnet and coil (refer to figure 1)? Which is the objective truth? In Einstein’s mind, he saw that the existence of electric or magnetic field is relative. Only taken together as electromagnetic fields can they be “ascribed a kind of objective reality” . This, according to Einstein leads to his conviction of the First Postulate.
My best fit line didn't pass through the origin, although it came very close. This is probably because the iron rod became slightly magnetised and acted as a weak permanent magnet, before it was connected.
The Effect of Increasing Number of Turns in a Coil on an Electromagnet It Is Capable of Holding
metal situate in the same fassion also creating a magnet. Now that we know the
... middle of paper ... ... conductor is moving parallel to the field; hence, no voltage is generated.
2. CONDUCTION - the metal cups will get hotter as a result of the heat
The discharge current flows through the stimulating coil to generate the necessary magnetic pulse. This pulse induces current in electrically conductive regions of the human body. If the induced current is of high amplitude and duration it will stimulate neuromuscular tissue in the same way as with conventional electrical stimulation. The first commercial magnetic stimulators originated from Sheffield in 1985 [16-21]. A typical magnetic stimulator consists of a capacitor charging or discharging alternatively with the appropriate control and safety electronics. Using the charging circuitry the energy storage system (capacitor) is charged to a level which can be up to a maximum of 3000 volts (kV) depending on the device. When the device receives an input signal as a trigger, the energy stored in the capacitor is discharged into the stimulating coil. The stored energy, with the exception of the energy lost in the wiring and capacitor, is transferred to the coil and then returned to the instrument to reduce coil heating. The discharge system consists of a switch and an electronic device, either a power metal oxide semiconductor field effect transistor (MOSFET) or insulated gate bipolar transistor (IGBT) or silicon controlled rectifier (Thyristor), and is capable of switching large currents in a few microseconds. Power MOSFETs, IGBTs and Thyristor conduct current only in one direction. As indicated in Figure 1 there are two types of waveforms: monophasic or biphasic which is commonly found in magnetic stimulation
...nt of individual conductors cutting through the magnetic field, the amount of induced voltage produced will be the sum of all the individual loops of the coil.
In 1831, using his "induction ring", Faraday made one of his greatest discoveries - electromagnetic induction: the "induction" or generation of electricity in a wire by means of the electromagnetic effect of a current in another wire. The induction ring was the first electric transformer. In a second series of experiments in September he discovered magneto-electric induction: the production of a steady electric current. To do this, Faraday attached two wires through a sliding contact to a copper disc. By rotating the disc between the poles of a horseshoe magnet he obtained a continuous direct current. This was the first generator. From his experiments came devices that led to the modern electric motor, generator and transformer.
The “head”, or device used to transmit data onto the magnetic disks, is an important part of the hard disk and composes most of the physical events. Current is passed through the head or in the physic’s case, the conductor, to produce a magnetic field around the conductor. This magnetic field can influence the disk’s magnetic material. The head is driven by an electric motor, using electromagnetism, to exert pushing and pulling forces on magnets to the rotating shaft. In some cases the head moves to a required area on the disk, and the motion of the magnetized surface induces tiny voltage.
The pieces of puddle iron were later brought to the construction site and held together using rivets.3
...placing a soft metal core (commonly an iron alloy) inside a coil of wire through which electric current passes in order to produce a magnetic field. The strength and polarity of the magnetic field changes depending on the magnitude of the current flowing through the wire and the direction of the current flow. While there is sufficient flow of current, the core behaves like a magnet; however, as soon as the current stops, the magnetic properties also disappear. Modern devices that make use of electromagnets are the televisions, telephones, computers and electric motors.