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An electromagnet can be made from a coil of wire and a soft iron core - OCR Gateway - GCSE Physics Combined Science - Question 14 - 2023 - Paper 5
Question 14
An electromagnet can be made from a coil of wire and a soft iron core. A student investigates how the strength of an electromagnet varies with the number of turns. ... show full transcript
Worked Solution & Example Answer:An electromagnet can be made from a coil of wire and a soft iron core - OCR Gateway - GCSE Physics Combined Science - Question 14 - 2023 - Paper 5
Step 1
Describe how the experiment is done using Fig. 14.1.
Answer
To perform the experiment, follow these steps:
- Setup: Secure the soft iron core upright. Wrap the copper coil around the soft iron core for several turns. Ensure that the coil is connected to a power source, such as a battery.
- Measurement: Use an appropriate method, like a compass or a small ferromagnetic object, to measure the strength of the electromagnet.
- Variation: Change the number of turns in the coil systematically. For example, start with 10 turns, then increase to 20, 30, and so on, ensuring to note each count.
- Data Collection: Record the strength of the electromagnet corresponding to each number of turns. It’s essential to repeat each measurement to ensure reliability and take an average reading if necessary.
Step 2
Explain what the graph in Fig. 14.2 tells us.
Answer
The graph in Fig. 14.2 illustrates the relationship between the strength of the electromagnet and the number of turns in the coil. As the number of turns increases, the strength of the electromagnet also increases, indicating a direct relationship. This trend suggests that each additional turn enhances the magnetic field created by the electric current flowing through the wire. At a certain point, the graph may begin to plateau, showing that increasing the number of turns beyond a specific quantity provides diminishing returns in strength. Overall, the graph confirms the principle that more turns in the coil yield a stronger electromagnet.