Download Electric Circuits KEY

9.
What voltage would the electrical meter show in each of the diagrams below?
1.5 V
10.
Why can you safely handle a 1.5-V battery without being electrocuted?

11.
15.
Water reduces the resistance of the skin from 100,000 ohms to a lower level
which might allow dangerous current levels to flow through your body.
Explain why electrical wires are made of copper covered in a layer of plastic.

14.
Conductors allow current to flow while insulators block the flow of current.
Why is it important to always have dry hands when working with electric circuits?

13.
The resistance of dry skin is very high. It will not allow enough current to flow to
be harmful.
What is the difference between a conductor and an insulator?

12.
0V
Copper is a very good conductor. The covering material acts an insulator to the
wire from making contact with objects that should not be exposed to the current
and voltage of the conducting copper wire.
Classify each of the following as a conductor, semiconductor, or insulator.
a. Copper
Conductor
b. Plastic
Insulator
c. Rubber
Insulator
d. Silicon
Semiconductor
e. Iron
Conductor
f. Glass
Insulator
What is the difference between a fixed resistor and a variable resistor? What is another
name for a variable resistor?

Fixed resistors have a resistance that cannot be changed. Variable resistors can
be adjusted to have a resistance within a certain range.