Electricity
19 questions tagged Electricity — spanning every one of the seven Ws.
Why does lightning follow a zigzag path?
Lightning travels through air in stepped bursts because air is normally an insulator. The electric field breaks the air down along the easiest ionized path, which twists and branches.
Whose experiment first showed that lightning is electricity?
Benjamin Franklin is associated with the kite experiment of 1752, which showed lightning is electrical in nature. It became one of the most famous experiments in science history.
Whose law relates the current, voltage and resistance in an electric circuit?
Ohm’s law, named after Georg Simon Ohm. It states that current equals voltage divided by resistance.
Whose law links current, voltage, and resistance in an electric circuit?
Ohm’s law, named after Georg Simon Ohm. It states that current equals voltage divided by resistance.
How does lightning form inside a thunderstorm?
Lightning forms when electrical charges build up in storm clouds and the air suddenly breaks down as a conductor. The resulting discharge can heat air to about 30,000 °C, several times hotter than the Sun’s surface.
Why do some materials conduct electricity while others do not?
Materials conduct electricity when they have electrons that can move freely through them. In insulators, electrons are tightly bound to atoms, so electric current cannot flow easily.
Why does electric current produce heat in wires?
Current produces heat because moving electrons collide with atoms in the material and lose energy. That energy becomes thermal motion, which is called electrical resistance heating.
What is an electric current?
An electric current is the flow of electric charge through a conductor or circuit. It is measured in amperes, or amps.
What is electric potential difference?
Electric potential difference, or voltage, is the difference in electric energy per unit charge between two points. It is what drives current through a circuit.
What is electrical resistance?
Electrical resistance is how much a material opposes the flow of electric current. It is measured in ohms.
Which fundamental force acts on particles with electric charge?
The electromagnetic force acts on particles with electric charge. It can attract opposite charges and repel like charges.
Whose law described how the force between electric charges changes with distance?
Charles-Augustin de Coulomb formulated Coulomb’s law in 1785. It says electric force follows an inverse-square relationship.
How do physicists calculate the force between two charged objects?
They use Coulomb’s law, which says electric force gets stronger with larger charge and weaker with the square of the distance. Opposite charges attract and like charges repel.
Why does static electricity build up more in dry air?
Dry air is a poor conductor, so electric charge does not leak away easily. That lets charge accumulate until it discharges as a shock or spark.
Why do electric eels produce strong shocks?
Electric eels use electrical discharges to stun prey, defend themselves, and navigate murky water. Their specialized cells can generate hundreds of volts in powerful bursts.
Which fish has the strongest known electric shock?
The electric eel can deliver shocks of up to about 860 volts, making it the strongest natural bioelectric generator known.
How does static electricity build up and create a shock?
Static electricity builds when electrons transfer between surfaces, leaving one object more negative and another more positive. A shock happens when the charge suddenly jumps through the air.
How does a lightning strike happen between clouds and the ground?
Lightning forms when separated electric charges create a huge voltage difference. Once the electric field is strong enough, air breaks down and conducts a powerful discharge.
How do electric rays stun prey without teeth or claws?
Electric rays have paired electric organs that produce shocks to immobilize prey or defend themselves. The organs are made from modified muscle cells.