CHAPTER 4: Results and Discussion4.1 ResultsB(Magnetic field strenght)I(Power)L(Conductor length)F(Lorentz force)

18,65x 2,97 A5xm276,95

18,65x 2,97 A1 xm55,39

4.2 DiscussionIn this lab, we discuss about the electric motor., Electric motors that we made was the fan. Practicum conducted to analyzing the equation how large and small a fan, analyzing the working principle of the dynamo, analyzing the function of the magnetic field, and analyzing the working principle of fan. First we prepare tools and materials such as, battery, battery house, wire, cable, dynamo, coil wire, magnets, board, ruler, buffer, scissors, glue, plug, razor / blade and used beverage bottles. Next, we made a windmill for the fan. Used beverage bottles that we cut up to resemble a windmill that can be used. As shown below:

After all the tools and materials are prepared, we stringing wire circuit with the above buffer circuit board in such a way, then connected to the current source is a battery and a wire coil to see the working principle of the dynamo. The working principle of the dynamo is more coils of wire are used, then rotate the greater speed and flow required will be greater.Because the dynamo that we make are not effective, so, to complete the circuit we use a ready dynamo. Dynamo is attached to the buffer, the cable is connected from the current source to the dynamo, and then connected to the switch. Dynamo were placed on the buffer, we seal with the top of bottles piece, then connected with the mill using the connecting wire (conductor length). The dynamo we attach with glue, so that once turned on the fan rotate properly.Here we perform two experiments where the connecting wire (conductor length) we cut to different sizes. the conductors length are 5 cm and 1 cm. From the experiments we did can be concluded that if the conductor is shorter, the fan will rotate faster. With the data we collect we define the Lorentz force using the formula:

F = BILwhere

Note :F= Lorentz forceB = Magnetic field strenght(T)a= the radius of the wire loop (m)I= Power (A)o= 4 x 107in standard unit

From these data, we perform calculations of magnetic field strength in advance to be able to search for Lorentz force, and we obtain the magnetic field strength is 18,65x . Magnetic fields strenght can be found if a strong current is already known, and has been measured in practice.In the current measurement in practice we get a large current is 2.97 A, where no agreement between theory and practice, this could have been caused by a battery that has been used previously.Furthermore, we perform calculations and obtain the Lorentz force for conductor length of 5 cm or 5xm is 276,95. And the Lorentz force for the conductor length of 1 xm is 55,39.

CHAPTER 5 : CLOSING5.1 Conclusion1. The length of the wire conductor, then the slower rotation of the windmill.2. The more coils of wire, the more rapidly rotating windmill, and the more current used.3. The larger the size of the mill, the more coils needed to spin.4. The more coils, the greater the required current.

5.2 SuggestionFor optimal results we recommend using AC current, because if you only use the battery current source, then the time it takes to spin very little.

APPENDIX

BOTTEL

BUFFER

GLUEBATTERY

DYNAMO HAS BEEN OPENDYNAMO

CABLEMAGNET

WIRE CONDUCTORBATTRY HOUSE

BREAD BOARDSWITCHLABORATORY INSTRUCTIONS ELECTRIC MOTORS

Purpose1. Find the lorentz force2. Explain the working principle of the dynamo

Tools and MaterialIn this experiment we use tools and equipments below: Magnet Coil Wire Batteries Cables Board Baling Propeller Dynamo

Theoretical BasisThe electric motor is a tool to convert electrical energy into mechanical energy. Tool that serves the opposite, converting mechanical energy into electrical energy is called a generator or dynamo. The electric motor can be found in household appliances such as fans, washing machines, water pumps and vacuum cleaner. In the electric motor power is converted into mechanical energy. This change is done by converting electricity into magnetism called electromagnets. As we know that the same poles of the magnets will repel each other and different poles attract each other. Then we can obtain the movement if we put a magnet on a rotatable shaft, and another magnet at a fixed position. The electric motor is an electromechanical device that converts electrical energy into mechanical energy. This mechanical energy is used to rotate the pump impeller, fan or blower, drive the compressor, lifting materials, etc. Electric motors are used in household appliances such as mixers, electric drill, fan and in industry.

The working principle of a DC motor is very similar to the simple linear machine. The image below shows a series DC motor.

DC voltage source VT associated with resistance RA and a switch that is closed at t = 0 on a pair of rails conduction. A stem conduction is shifted to rail. Assuming the rail and trunk no resistance, formed the magnetic field leads to the image plane, perpendicular to the field of rail and trunk.Suppose the rod does not move when the switch is closed at t = 0. Shortly after the switch is closed, arising iA current that flows clockwise around the circuit. The resulting electric force on the rod is

The direction of this force is to the right.

This force causes the rod to move to the right. Because the stem has particularly speed u meotong magnetic field lines, the induced voltage is formed along the stem. The magnitude of the positive voltage at the upper end of the rod and is expressed by the equation.

Equivalent circuit for this system is shown in the figure below.

It should be noted that eA induced voltage in the opposite direction to the voltage VT. Currents generated due to the influence of the induced voltage is

With the formation of the rod speed, energy is absorbed through the induced voltage eA, and this energy is shown as kinetic energy in the trunk.

ProceduresProving the working principle of the dynamo1. prepare the tools and equipments needed to the make the circuit.2. Take a magnet and stick magnets on the board that has been available.3. Create a buffer above the magnet.4. Place the battery on the board.5. Take the cable and connect the battery to buffer the cable is made of wire.6. Create a wire coil as spindle.7. place the wire coil in a buffer.8. Attach the propeller at the end of the coil wire.9. Connect the cable and betere with wire buffer.

1. Prepare the tools and materials, battery, home batrre, wires, cables, dynamo so, coil wire, magnets, board, ruler, buffer, scissors, glue, plug, razor / blade and used beverage bottles.2. Make the propeller of the bottles, using one end of which is that the bottom of the bottle. Cut up like a propeller.3. Attach the dynamo in the buffer.4. Connect the battery and contacts on / off by using a cable.5. Cut the conductor into 2 sizes: 5 cm, and 1 cm.6. Attach the length of the conductor on the dynamo. And closed by using the tip of the other bottles.7. After making sure fitting, then connect the conductor length denagn propeller.8. Enjoy a small fan that moves.

Observation ResultB(magnetic field strenght)I(power)L(conductor lenght)F(Lorentz force)

Conclution

Score