Magnetic Fields and Electric Charges

This lesson explores the concepts of electric and magnetic fields, their interactions, and how they combine to form electromagnetic radiation. It covers the properties of these fields, historical discoveries by Oersted and Faraday, and the principles of electromagnetic induction. The lesson includes experiments demonstrating the effects of electric currents on magnetic fields and vice versa, providing a foundation for understanding electromagnetic waves.

What is required for electromagnetic radiation to travel outward?

• A solid object

• Oscillating electrons

• A vacuum

• A medium with particles

What happens when a positive charge is brought near another positive charge?

• They combine to form a larger charge

• They remain neutral

• They repel each other

• They attract each other

What is the effect of an electric charge moving on the electric field at a faraway point?

• The field changes instantly

• The field changes after some time

• The field disappears

• The field remains unchanged

What is a characteristic of a magnetic field around a bar magnet?

• It only affects objects in direct contact

• It extends to faraway points

• It is invisible and has no effect

• It is only present at the poles

Who were the scientists that showed the connection between electricity and magnetism?

• Isaac Newton and Albert Einstein

• Hans Christian Oersted and Michael Faraday

• Nikola Tesla and Thomas Edison

• James Clerk Maxwell and Heinrich Hertz

What happens to the magnetic needle when electric current flows through a wire?

• It stops moving

• It moves away from the wire

• It swings to right angles to the current

• It remains parallel to the wire

What is the direction of the magnetic field around a wire if the current flows upwards?

• Anti-clockwise

• Clockwise

• Vertical

• Horizontal

What happens to the magnetic field when the direction of the current changes?

• The field becomes stronger

• The field disappears

• The field changes direction

• The field remains the same

What is generated when a magnetic field changes around a wire?

• Electric current

• Light

• Heat

• Sound

At what angles are the electric and magnetic fields to each other?

• 90 degrees

• 180 degrees

• Parallel

• 45 degrees