Materials
Field Lines
Coulomb's Law
Charging & Charges
MISC
100
Which material is most commonly used to move electric charge?
Conductor
100
Identify the charge of the charged object on the left.
Positive
100
What is the value of the Coulomb's Law constant?
k = 9.0E9 Nm2/C2
100
Rubbing rabbit fur on an acrylic (plastic) rod is an example of...
Charging by Friction
100
Like _________ Like but Opposites __________.
Repels, Attract
200
If the electrons in an object cannot freely move, they are in _____________.
an insulator
200
Give the three requirements for electric field lines.
Point away from a positive charge
Point towards a negative charge
Never cross
200
What does q stand for in Coulomb's Law?
the charge of the object. We have two q's because there must be two charges to create an attractive/repulsive force.
200
What type of charging does not require contact?
Induction
200
What type of energy causes two charges to repel?
Electric Potential Energy
300
TRUE or FALSE: When charging a conductor and insulator, the insulator is more likely to lose its electrons. Explain your answer.
FALSE! Insulators do not lose electrons easily whereas conductors do.
300
Describe how the electric fields interact for a repulsive force.
Verbal description of this image:
300
What kind of relationship do the electrostatic force and the distance between charges have?
Inverse
300
A glass rod is charged with silk cloth charging the rod with a +3nC charge. What charge does the silk cloth obtain from this interaction?
-3 nC
300
What does an electroscope do?
Shows the presence of a charge QUALITATIVELY
400
Which type of technology became more compact and portable thanks to advances in using semiconductors?
computers / processors
400
What about the electric field lines tells you that an object has a greater charger?
More lines = more charge
400
What is the force exerted by two 4.3 x10-5 C charges that are 2m apart?
4.15 N
400
If you are looking to balance the forces between two charges that are similar in polarity but different in magnitude, where do you put the charge?
closer to the smaller charge.
400
What did Millikan discover with his experiment? How did he do it?
Charge of an electron by studying the repulsive electrostatic force.
500
Explain why cost-effective superconductors would be beneficial to our society.
Much more efficient transfer of electrons without the heat/pressure requirements that make it cost-prohibitive.
500
How do you know a charge is closer to another charged object based on the electric field lines?
There are more of them (the field gets stronger as you get closer).
500
A force of 7N is exerted by two similar charges that are 80 cm apart. What is the force when the charges are 20cm apart?
112 N
500
The Van der Graaf generator gives Ms. Busby a -3 charge. Ms. Engel has a -7 charge just by walking and building up charge from his socks. Ms. Engel gives Ms. Busby a high-five and receives a short shock. What charge(s) do they each have now? [Assume charges are not grounded by any other source]
-5 charge
500
A positively charged particle is shot between two plates. It does not move toward either plate and picks up speed as it shoots between them. What do you know about the plates?
They are both positive.