Podcast
Questions and Answers
What is a magnetic field?
What is a magnetic field?
- The space around a compass needle
- The region around a magnet where the magnetic force acts on magnetic materials (correct)
- An imaginary line connecting the north and south poles of a magnet
- The area where the pull of gravity is stronger
How can you tell if a metal bar is magnetic?
How can you tell if a metal bar is magnetic?
- By observing it under a microscope
- By dropping it in water to see if it floats
- By placing iron fillings around it to observe the magnetic field pattern (correct)
- By heating it up to see if it changes color
What creates the Earth's magnetic field?
What creates the Earth's magnetic field?
- Static electric charges on the Earth's surface
- Movement of molten iron and nickel in the Earth's core producing electric currents and magnetic fields (correct)
- The rotation of the Earth on its axis
- The gravitational pull of the Moon on the Earth
What is the purpose of a compass on Earth?
What is the purpose of a compass on Earth?
How do magnets behave when opposite poles are brought close together?
How do magnets behave when opposite poles are brought close together?
What is a line of force in magnetism?
What is a line of force in magnetism?
What is the main characteristic of a magnetic field?
What is the main characteristic of a magnetic field?
Why do magnetic field lines become denser when opposite poles of two magnets are brought closer?
Why do magnetic field lines become denser when opposite poles of two magnets are brought closer?
What contributes to making an electromagnet stronger?
What contributes to making an electromagnet stronger?
Why is the Earth's magnetic field stronger at certain regions?
Why is the Earth's magnetic field stronger at certain regions?
What is the significance of a compass needle having a north-seeking pole?
What is the significance of a compass needle having a north-seeking pole?