Static Electricity Flashcards
(22 cards)
How can an insulator be charged by friction?
By transferring electrons between materials when rubbed together.
What happens to a material that gains electrons?
It becomes negatively charged.
What happens to a material that loses electrons?
It becomes positively charged.
What is the rule for charges?
Same charges repel, opposite charges attract.
What causes static shocks from everyday objects?
Discharge of static electricity built up on the body or object.
How is lightning caused?
By the build-up and discharge of static electricity in clouds.
How does a charged balloon stick to a wall?
By inducing an opposite charge on the wall’s surface.
How can a charged comb pick up paper?
By inducing opposite charges on the paper pieces.
What does earthing do?
It removes excess charge by allowing electrons to flow to or from the ground.
How does insecticide spraying use electrostatics?
Charged droplets repel each other and spread evenly on surfaces.
What is a danger of sparking?
It can ignite flammable gases or liquids.
Why is earthing used when fuelling vehicles?
To prevent dangerous build-up of static charge.
What is an electric field?
The region where an electric charge experiences a force.
What does the direction of electric field lines show?
The direction a positive charge would move.
What does the density of electric field lines indicate?
The strength of the electric field.
What is the electric field around a point charge like?
Radial lines pointing away (positive) or toward (negative) the charge.
What is the electric field between parallel plates like?
Uniform — lines are straight, parallel, and equally spaced.
What happens when a charged object is placed in an electric field?
It experiences a force.
What does the force on a charged object depend on?
The strength of the electric field and the size of the charge.
How can static electricity be reduced?
Using antistatic sprays, earthing, or humid conditions.
What is charging by induction?
Creating a charge without direct contact, by rearranging charges in a nearby object.
Why do oppositely charged objects attract?
Because the electric field lines from one are drawn to the other.
