Efficiency Of The Motor 1 0 example essay topic

The aim of this experiment is to compare the electrical energy used to operate a motor with the potential energy gained by a mass raised by the motor. Materials: 1.1 motor 2. String 3.1 spool 4. Ammeter 5. Voltmeter 6.7 insulated cables 7. Stand to hold the motor 8.1 switch 9.1 rheostat 10.1 power pack 11.3 x 10 gram weights Procedures: 1.

Set up a circuit as shown in figure 50-1.2. Tie the cotton to the spool and attach the spool to the motor 3. Tie a ten gram weight onto the end of the cotton string 4. Dangle the weight over the side so it is just touching the ground 5. Turn the motor on and adjust the resistance using the rheostat to get the weight to a point where it is being lifted at a constant rate.

6. Measure the time it takes for the weight to reach the very top 7. Record the amps, volts and time it takes for each turn twice. 8. Repeat step 1 to 7 for the 20 and 30 gram lifts.

Results: Trial Mass (kg) Distance (m) Volts (V) Amps (A) Time (secs) 1.0. 01 1 0.49 0.38 2.36 2.0. 01 1 2.54 3.0. 02 1 0.68 0.49 2.41 4.0. 02 1 2.32 5.0. 03 1 0.81 0.72 2.30 6.0.

03 1 2.03 Electrical energy formula: E = VIT Potential energy formula: P e = MGH Motor efficiency formula: M eff = Energy used x 100 Potential energy Trial Electrical energy used (VIT) Potential energy given (MGH) Efficiency of the motor 1.0. 439 0.0987 22.48% 2.0. 474 20.82% 3.0. 803 0.196 24.41% 4.0.

772 25.38% 5.1. 344 0.294 21.88% 6.1. 181 24.89% Questions: 1. What was the average efficiency of your motor? Efficiency % total = 139.59 = 23.265% 6 6 2.

List several factors that contribute to lack of efficiency of such motors. Some of the major factors that causes these motors to not work to their full potential is that a lot of energy is lost through heat, sound, friction between the brushes and bearings, vibration and air resistance. This energy loss contributes to a large majority of the lack of efficiency. 3. Draw the circuit that you used to conduct this experiment.

4. When working with electric motor you probably noticed that the motor turned faster as more current was supplied to it. Why did this occur? The reason for the increase in speed was because I (or amplitude) is proportional to torque.

The more torque you have the more velocity you have. Therefore if you apply more amps the torque increases as well. 5. Why is it important for the mass to rise steadily with no acceleration if you are to obtain a correct measurement of the work done by the motor? Obtaining a constant speed is essential due to the fact that if the mass accelerates some of the electrical energy is converted into kinetic energy rather then potential energy.

CONCLUSIONS Overall our experiment was a success our results were achieved with minimal error and to great accuracy. However there were a few problems and errors that we noted throughout the prac. These being: . Tying a simple Granny knot that would last throughout the entire experiment... Getting the weights tied on to the end of the cotton... Getting the spool to stay on the motor without it wobbling...

Getting the weight to lift at a constant speed... Recording the time exactly when the weights started and stopped. These errors and problems would have affected our results. However this affect would have been minimal as we tried our best to overcome them. To overcome these errors we did the following: . Experimented with different knots and found that doubling over the cotton held on to the spool and weights much better...

Carefully selecting the spool to get the one that wobbled least... Ran "test runs" to get the weights lifting at a constant speed... Got the person that started and stopped the experiment to start and stop the watch as well so that the human error was minimal. This experiment was extremely easy and fun to conduct. It could have been improved with ideal equipment and ideal conditions. From our results it is clear that the energy that is put into the motor was clearly not being used to its full potential.