Question 1: What is the primary characteristic of a magnetic field?

Answer: It exerts a force on magnetic materials and electric currents.

Question 2: True or False: Magnetic poles always exist in pairs, north and south.

Answer: True

Question 3: True or False: A permanent magnet loses its magnetism over time without external influence.

Answer: False

Question 4: Define the term 'magnetic flux'.

Answer: Magnetic flux is the measure of the total magnetic field passing through a given area.

Question 5: Explain how a compass works using the Earth's magnetic field.

Answer: A compass needle aligns itself with the Earth's magnetic field, pointing towards the magnetic north and south poles.

Question 6: What happens to the magnetic field around a wire when electric current flows through it?

Answer: When electric current flows through a wire, it creates a circular magnetic field around the wire.

Question 7: Calculate the force on a 2-meter wire carrying a 3 A current perpendicular to a 0.5 T magnetic field. Use the formula F = BIL.

Answer: 3 N

Question 8: Match the following terms to their definitions:

Answer: See full answer key

Question 9: Order the steps involved in creating an electromagnet.

Answer: See full answer key

Question 10: Fill in the blank: The region around a magnet where magnetic forces can act is called the ______.

Answer: magnetic field

Question 11: Discuss the impact of Earth's magnetic field on modern navigation systems. Include both benefits and limitations in your answer.

Answer: Earth's magnetic field plays a critical role in navigation by enabling compass use, providing a natural directional guide. This benefits traditional navigation and is a backup for modern systems. However, magnetic field variations can affect accuracy, and reliance solely on it can be misleading, necessitating supplementary systems like GPS for precision. Earth's field also protects electronics from solar radiation, although high-altitude and polar regions face increased magnetic interference risks.