Electricity Exam
Formulas: V = IR and P = IV

Answer questions completely and correctly.  Show your work wherever any is required.

What subatomic particle moves through conductors in an electric current?

Attract, repel, or nothing
___________ Electron and electron
___________ Neutron and electron
___________ Proton and electron
___________ Proton and proton

Why did the water sometimes bend in its path when a balloon was brought close?

Give an example of how you could create a static electric charge.

Give three examples each of
conductors: 1) 2)3)

insulators: 1) 2) 3)

Draw the electric field between two opposite charges.

Give an example three of the following (if you answer all four, only the first three will be graded):
an electrochemical cell.

a photoelectric cell.

a thermoelectric cell.

a piezoelectric cell.

In the hose analogy of electricity:
What does the water itself represent?

What do you do to change the current?

What do you do to change the voltage?

Give an example of a technology a semiconductor might be used in.

Give an example of a technology a superconductor might be used in.

Does current run through an open switch or a closed one?

Why is it better to have a circuit breaker than a fuse?

Why is the symbol for a resistor a jagged line?

What is the advantage of connecting things in parallel rather than in series?

Answer the following questions about the schematic below:

Is this a series circuit or a parallel circuit?

If I turned off the switch, how many bulbs would still be lit?

If a 4 V battery is connected to a small light bulb with a resistance of 3.5 Ohms, what will be the current in the bulb?
What are the following variables worth?  (Put a question mark by the variable the problem is asking for.  If a variable is not mentioned, scratch it out.)
I = ________R = ________V = ________P = ________

Which equation should you use?

How should it be rearranged (if at all) to solve for the unknown?

“Plug in” the values and solve it.

What is the current in a bulb that requires 120 V with a power rating of 75 W?
What are the following variables worth?  (Put a question mark by the variable the problem is asking for.  If a variable is not mentioned, scratch it out.)
I = ________R = ________V = ________P = ________

Which equation should you use?

How should it be rearranged (if at all) to solve for the unknown?

“Plug in” the values and solve it.

What is the voltage in a bulb that draws 5 A with a power rating of 75 W?
What are the following variables worth?  (Put a question mark by the variable the problem is asking for.  If a variable is not mentioned, scratch it out.)
I = ________R = ________V = ________P = ________

Which equation should you use?

How should it be rearranged (if at all) to solve for the unknown?

“Plug in” the values and solve it.