Show:
9.1 & 9.2
9.3, 9.4, 9.5
random!!
10.1 & 10.2
10.3,10.4,10.5
100
When two socks made of the same material are both rubbed with a sweater, what happens to the socks?
The socks would attract because they are made of the same material and they are both rubbed by the sweater.
100
What is the difference between an insulator and a conductor?
It is not easy for an insulator to give up or receive electrons while a conductor allows electrons to flow freely from one atom to another.
100
A voltage will influence current only if the current is...
closed.
100
What is the SI unit for measuring energy?
joules (J)
100
What is the color code for 220 ohms +/ 5%? (pretend that's a negative sign below the plus sign)
red, red, brown, silver
200
What is the name of the person who conducted a kite experiment and concluded that there are two types of electric charges?
Benjamin Franklin.
200
Why is the paper that has a negative charge in the the printer able to pick up the toner, even though the drum is also negative?
Because the paper is more negatively charged than the drum. The electric force between the toner and the paper is greater than the electric force between the toner and the drum.
200
What is the study of electric charges called?
electrostatics
200
The flow of conventional current starts from the positive terminal to the negative terminal of the energy source.
True.
200
How do you differentiate the symbol for the variable voltage and the unit volt?
variable voltage is an italicized V and the unit volt is a regular V
300
What does the Law of Electric Charges state?
The Law of Electric Charges state that like charges repel and unlike charges attract.
300
True or false? If you stayed inside a metal sphere during lightning, you would get electrocuted. It is much better if you stay inside a rubber ball.
False. Because charges only stay on the surface of an object, you would actually be safe in a metal sphere. In a rubber ball, the lightning would much rather travel through a human than rubber, resulting in electrocution.
300
What is the name of the pressure that moves electrons in a closed circuit?
voltage
300
a) Ammeters are always connected in ________ in a circuit, and voltmeters are always connected in _________. b) Why do voltmeters need to be connected in _______?
a) series and parallel. b) Voltmeters need to be connected in parallel so a small amount of current goes through the voltmeter and the rest of the current goes through the load.
300
In a circuit, what does an electric cell provide electrons with?
electric potential energy.
400
When you rub your feet on the carpet and touch the doorknob, you will most likely receive a shock. Would the same thing happen if you were floating? Explain.
Yes, you would still receive a shock even if you are not touching the ground. The ground is not what provides you electrons to transfer to the doorknob.
400
What does Coulomb's law state?
Coulomb's law states that the strength of electric forces increase with increasing electric charges and decreases with increasing distance.
400
What voltage will be developed across a 560Ω resistor if a current of 20mA is flowing through it?
Formula: V= IR V= 0.02 x 560 V= 11.2 V
400
a) What is the difference between primary and secondary cells? b) What do primary and secondary cells have in common?
a) Primary cells cannot be recharged because the chemical reactions are irreversible while secondary cells can be recharged using electrical energy to reverse the chemical reactions. b) Both primary and secondary cells contain an electrolyte and a positive and negative electrode
400
What happens with the voltage when two electric cells are in a series?
the electric cells give the current twice the voltage
500
You bring a charged rod near a neutral metal sphere. Did you actually charge the metal sphere? Explain.
The metal sphere is not uniformly charged. There is only a change in the positions of the charges. Only a certain area of the sphere is charged.
500
In the formation of lightning, what happens that makes Earth acquire a strong positive charge?
When the negative charge at the bottom of the cloud is strong enough, the electrons on the ground are repelled and the positive charge becomes strong on the surface of the ground.
500
Bob didn't perform the experiment that his teacher told him to do, so he decided to fake the experiment. He reported: He rubbed the acetate and brought it near a positive object and the objects repelled each other. After 30 minutes, Bob used the acetate he used previously without doing anything else with it near a negative object and they attracted. The teacher instantly knew that Bob did not do his experiment. Explain.
Although all the actions of the electric forces were correct, the acetate was not charged during the second time. The static charge will eventually be discharged.
500
How much current is flowing when 29.3 Coulombs of charge pass a point in 7.84 seconds?
Formula: I= Q/T I= 29.3 C / 7.84 s I=3.7372449 C / s ( 1 C / s = 1 A ) I = 3.74 A
500
A voltage source applies 60 V to two identical resistors. (will be given to you in sec) a) What is the voltage of each resistor? b) If the current leaving the voltage source is 400 mA, what is the resistance of each resistor?
a) 30 V b) R= V/I R= 30/ 0.4 R= 75 ohms