Chapter 22: Electrostatics Flashcards
What is Coulomb’s Law?
The relationship between distance and electrical forces. Electrical force decreases inversely as the square of the distance between charged bodies. F1 = k(q1q2)/d^2
What is an electric field?
A force around an object that extends through space, and has magnitude and strength. The force per unit charge. Force/Coulumb
What is a positive ion?
The extra + charge of an atom that is not equally balanced (positive charges = negative charges)
What is a negative ion?
The extra - charge of an atom that is not equally balanced (positive charges = negative charges)
State the Conservation of Charge.
No electrons are created nor destroyed, only transferred.
What is a conductor? Give an example.
When the electrons in the outer atomic shell of an atom is “loose” and can wander freely in the material, for example, metal is a good conductor.
What is an insulator? Give an example.
When the electrons are tightly bound and cannot wander freely, for example, rubber and plastic are good insulators.
What is a semiconductor? Give an example.
A material that can be made to either be a conductor or insulator. For example, germanium and silicon are neither good conductors nor good insulators.
What is a superconductor?
A material that acquires zero resistance to the flow of charge.
How can you charge by induction?
Take two equally charge spheres touching together. Next place a negatively charged rod near (not touching) Sphere A. Because opposites attract and like repels, the positive charges will collect in Sphere A, while the negative charges will collect in Sphere B. Then pull the spheres apart with the rod still present and Sphere A will be positively charged. Sphere B will be negatively charged.
How can you charge by friction?
Simply touching a material can transfer electrons. For example, if you pet a cat’s fur eventually you will start to hear the crackling of sparks produced.
What is charge polarization?
When a material such as insulator does not have any extra charge to move, the surface molecules rearrange due to the attraction or repelling action. For example, if a negative rod is placed near a surface, the atoms closest to the rod will rearrange (positive will move closer, negative will repel) causing a distortion of the field.
Define electric potential.
The work required to push a charged particle against the electrical field of a charged body in relation to the charged particles location within the charged body. When released, the particle accelerates in a direction away from the sphere and its electric potential energy becomes kinetic energy.
What is a capacitor?
A common device where electric energy can be stored.
