Electric Charge Definition

Electric & Magnetic Fields

Fun Facts

Clothes stick together due to transferred electrons creating opposite electric charges.
Toner in laser printers sticks to paper due to opposite electric charges.
Objects usually become electrically charged by rubbing against each other and transferring electrons from one area to another.

Why Do We Need To Know About Electric Charge

Studying electric charge helps us understand why devices we use every day work and why jobs in engineering and electronics matter. For example, our phone speakers make sound because of magnetic fields from electric charges, showing us how key electromagnetism is in tech.

Laser printers work by using electric fields. A drum with an electric charge pulls negatively charged toner onto paper. This use of electric charge is what allows us to print like we do today and creates jobs in making and bettering electronic gadgets.

Frequently Asked Questions

How can you increase the strength of the magnetic force on an object like a paper clip?

Magnetic forces get stronger as the magnet moves closer to the object it is attracting or repelling. If two magnets are made of the same material, then the larger magnet will have a stronger magnetic field. The strength of a magnet also depends on the material from which it is made. For example, neodymium magnets will have a stronger magnetic field than magnets made from Alnico (an alloy of aluminum, nickel, and cobalt).

Why can iron filings be used to visualize a magnetic field?

Each tiny piece of iron becomes magnetized, and its poles align with the lines of the magnetic field. Therefore, the iron filings will line up to show the field lines and can be used to determine the relative strength of the field. Closely packed lines indicate a stronger field; widely spaced lines indicate a weaker field.

How can two balloons repel each other without touching?

Balloons that have been rubbed with the same material will take on the same charge. Charged objects are surrounded by electric fields that can exert a force on other charged objects. Two balloons with the same charge will repel each other.