How does a variation of current through the windings of insulated wire affect the strength in the electromagnet?

Planning B

Diagram

Apparatus and materials

• DC Power kit
• Voltmeter
• Ammeter
• 12cm of nail
• Winding wire
• Wire and crocodile clamps
• Rheostat
• Spring balance

Method

1. Turn the wire 25 times around the nail to construct the electromagnet.

2. a) A secure crocodile clamp between winding wire and circuit at both ends.

b) Connect the wire with ammeter, voltmeter, rheostat and Power supply

3. a) Alter the input voltage and measure the changes voltmeter, ammeter and spring balance to measure the resultant electromagnetic force expressed in Newton

b) Repeat the experiment 12 different voltages to obtain sufficient data. Try increments of 1V from the power supply to 12V

c) Record three trials for each voltage (current)

4. If any significant random error occurs during the measurement, that value is to be ignored and the experiment to be repeated.

Data Collection

Data Processing and Presentation

Conclusion and Evaluation

As we can see from the graph, the force produced by the electromagnet is directly proportional to the current provided by the circuit. The standard deviation of the graph is not significant and is reasonably within the error margin.

More uncertainties were recorded when a low current was used. But the results were consistent throughout the whole experiment and very few measurements had to be repeated.

Overall I am satisfied with the experiment as my hypothesis was validated: the magnetic field strength of the solenoid is directly proportional to the current in the circuit, provided that all other parameters are unchanged.

The apparatus used for this experiment was satisfactory. The only device that we believe could be improved is the spring balance. A model with a finer scale could provide more accurate data. In our opinion, this could be the only improvement that we can suggest to the procedure. The data we collected was quite precise and easy to interpret.