GED Science TestPhysical ScienceMedium
A technician is setting up an electromagnet. They wrap a coil of wire around an iron core and connect it to a power source. To increase the strength of the electromagnet, which of the following actions would be most effective?
- AIncrease the current flowing through the coil.
- BDecrease the number of turns in the coil.
- CUse a non-magnetic core material like wood.
- DReverse the direction of the current.
Show answer & explanationAnswer & explanation
Correct answer: A. Increase the current flowing through the coil.
The strength of an electromagnet is directly proportional to the current flowing through its coil. Increasing the current will strengthen the magnetic field. Other factors include the number of turns and the type of core material.
Why the other options are wrong
- B. Decreasing the number of turns would weaken the electromagnet.
- C. Using a non-magnetic core would significantly weaken the electromagnet, as iron is a ferromagnetic material that concentrates magnetic fields.
- D. Reversing the direction of the current would reverse the polarity of the electromagnet, but not necessarily increase its strength.
Electromagnet Strength Factors
The strength of an electromagnet is determined by several factors, including the number of turns in the coil, the current flowing through the coil, and the nature of the core material.
- More turns = stronger field.
- Higher current = stronger field.
- Ferromagnetic core (like iron) = stronger field.
Memory trick: Electromagnet strength is built by 'Current, Coils, and Core'.