What is the name of a device that hangs from a stand and is used to show the build up of electric charge.
Pith ball
Where do the positive charges go when an ebonite rod is rubbed with silk?
*TRICK QUESTION*
The positive charges do not go anywhere!
Which subatomic particles are the ones that travel through conductors and carry charge?
Electrons
What is the more common term for the amount of electrical potential difference between two points on a circuit?
Voltage
What is the name of the device used to turn a current on and off without dismantling the circuit itself?
Switch
If an ebonite rod is rubbed with rabbit fur, then held close to a stream of running water, what will happen to the water?
The water will be attracted toward the rod.
What is the name given to a sudden jump of electrons from a negatively charged object to a positively charged object?
What is the name for a substance that does conduct electricity effectively?
Insulator
What is the name of the quantity that measures the amount of charge travelling in a circuit, and what units is it measured in?
Current, measured in amperes/amps.
In order to function, a circuit needs three basic elements: conductors, loads and a __________.
source (cell, battery, etc)
It keeps and attracts electrons very well.
What is the name of the device shown below?
Van de Graaff generator
What is the difference between "conventional current" and "electron flow"?
Conventional Current - what scientists used to think happens and how circuit diagrams are drawn
Electron Flow - what actually happens
(They go in opposite directions)
What are the units of measure for resistance?
Ohms (Ω)
To measure the voltage used in a light bulb, how must the voltmeter be connected to the circuit?
In parallel with the light bulb you want to measure.
Like charges repel. Opposite charges attract. What is the 3rd Law of Electrostatics?
A neutral object is attracted to a charged object.
How does a balloon stick to the wall after it has been rubbed on a wool sweater?
Balloon is negatively charged. When placed near a wall, it repels the electrons in the wall and creates a temporary positive area on the wall.
How is the current through ammeters 1, 2, 3 and 4 related?
I1 = I4,
I2 + I3 = I1
How much current will run through an electrical device that runs on two AA batteries and is built with 10 Ω of resistance?
V = 3 V and R = 10 Ω
I = V/R = 3/10 = 0.3 A
Describe Kirchhoff's Current Law.
The current going into any point of a circuit is equal to the current coming out of that point.
Explain how to induce a permanent positive charge on a pith ball.
How should a lightning rod be designed in order to protect a building? (Provide two main features)
-made of metal (conductive material)
-grounded to give electrons a pathway out of the building
How will IA and IB compare to each other if the switch is opened and closed?
With the switch open, IA = IB.
With the switch closed, IA = IB + IC
A circuit has two parallel branches. The first branch contains a single lightbulb rated for 10 Ω and uses 12 volts. The second branch has a current of 0.8 A.
What is the total resistance of the circuit?
1st branch: I = V/R = 12/10 = 1.2 A
2nd branch: I = 0.8 A
IS = 1.2 + 0.8 = 2 A
VS = V1 = 12 V
RS = VS / IS = 12/2 = 6 Ω
Describe Kirchhoff's Voltage Law
In any loop of a circuit, the voltage gained at the source is equal to the total voltage used at the loads in that loop.