Pass Check: Magnetism & Electromagnetism
Magnetic fields exert forces on magnets and moving charges; current-carrying wires create fields.
Magnetic field
The region around a magnet or current-carrying wire where a force is exerted on other magnets or magnetic materials.
Permanent magnet
A magnet that produces its own magnetic field all the time.
Induced magnet
A material that becomes magnetic when placed in a magnetic field and loses most of its magnetism quickly when removed.
Electromagnet
A magnet made from a coil of wire carrying a current, often wound around an iron core.
Quick check
Mixed quiz
1. Complete the sentence: The formula for the force on a current-carrying wire in a magnetic field (motor effect) is ______.
2. Complete the sentence: A plotting compass placed in a magnetic field will ______.
3. A wire carrying 5 A is placed in a magnetic field of 0.2 T and experiences a force of 0.4 N. Calculate the length of the wire in the field.
4. State what happens when two like magnetic poles are brought together.
5. Explain why increasing the number of turns on the coil of an electromagnet increases the magnetic field strength.
6. What are the two poles of a magnet called?
7. Complete the sentence: Earth's magnetic field makes a compass needle point roughly towards ______.
8. Complete the sentence: A permanent magnet always attracts magnetic materials ______.