# The Relationship Between the Current and the Strength of Electromagnet

Autor:   •  October 20, 2017  •  Essay  •  479 Words (2 Pages)  •  653 Views

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Aim:to find the relationship between the current and the strength of electromagnet

Introduction:This experiment will try to find the relationship between the current and the strength of electromagnet . The independent variable is current , dependent variable is the strength of electromagnet . The result will be get by changing the resistance on the rheostat which will be on the electric circuit . Then put the clips on the electromagnet and count how many of them are attracted to check the strength of electromagnet . Less number of clips means that the electromagnet is weaker .

Instruction：

[pic 1]

Hypothesis: If the current is strong , then the strength of electromagnet will also be strong .

Independent variable:current

Dependent variable: strength of electromagnet

Controlled variables: the mass and the type of clips ( need to be control , because if the clips are different , then the result won’t be exact ).

The total voltage of the electric circuit ( it should be controlled , because what else the result won’t be exact .

Instrument:rheostat,switch,electromagnet,power supply,ammeter,clips.

Procedures:

1. First build up the electric circuit . Connect the power supply with one side of the switch , so that the electricity will be able to pass through the circuit.
2. Check that everything is working .
3. turn on the switch and use the rheostat to let the current become 0.1A.
4. Take out the clips ,and put them on the electromagnet.
5. Collect the data of the amount of clips that are attracted by the electromagnet, the amount of clips will show the strength of the electromagnet . The experiment will be repeated 3 times for each value, then the final data will be the average of it .
6. Change the current to 0.15A , 0.2A,0.25A,0.3A, and repeat the process of counting and recording the amount of clips the same as the 5th step .
7. After finishing , turn off the electricity .
8. Put the data in a table .

Data collection and processing

 1 2 3 4 5 I(A) 0.1 0.15 0.2 0.25 0.3 No.of clips 5 14 28 35 62 No.of clips 8 18 30 42 50 No.of clips 8 13 24 37 60 mean 7 15 27 38 58

[pic 2]

Conclusion

The graph and the table shows that if the current is stronger , then the number of clips that are attracted will be bigger . Which means that the strength of the electromagnet will become stronger , if the current increase . The conclusion of this experiment is the current has a big influence on the strength of the electromagnet .

Evaluation and improvement .

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