1. What is an insulator?
A.
A material that allows electric current to flow easily
B.
A material that strongly resists the flow of electric current
C.
A material that produces electric current by itself
D.
A material that stores only magnetic energy
Correct Answer:
A material that strongly resists the flow of electric current
Explanation:
An insulator is a material that offers very high resistance to the flow of electric current.
2. Which statement best defines an electrical insulator?
A.
It has many freely moving charge carriers
B.
It permits current to pass without resistance
C.
It has very few free charge carriers
D.
It always carries a negative charge
Correct Answer:
It has very few free charge carriers
Explanation:
Insulators contain very few free charge carriers, so electric current cannot flow through them easily.
3. Why do insulators resist the flow of electric current?
A.
Their electrons are tightly bound to atoms
B.
Their atoms have no electrons
C.
Their electrons move freely through the material
D.
They contain a large number of mobile ions
Correct Answer:
Their electrons are tightly bound to atoms
Explanation:
In an insulator, electrons are tightly bound to their atoms and cannot move freely to conduct current.
4. Which of the following is a characteristic of an insulator?
A.
Low electrical resistance
B.
High electrical resistance
C.
High number of free electrons
D.
Easy flow of electric charge
Correct Answer:
High electrical resistance
Explanation:
Insulators are defined by their very high electrical resistance, which prevents the easy movement of charge.
5. An insulator is a material through which electric current flows:
A.
Very easily
B.
Only without a voltage source
C.
With great difficulty
D.
Only when it is magnetic
Correct Answer:
With great difficulty
Explanation:
Because an insulator has very few free charge carriers, current flows through it only with great difficulty.
6. Which material property is most closely associated with an insulator?
A.
Very high resistivity
B.
Very low resistivity
C.
Perfect transparency
D.
High thermal expansion
Correct Answer:
Very high resistivity
Explanation:
Insulators have very high resistivity, meaning they strongly oppose the movement of electric charges.
7. In an insulator, the charged particles responsible for conduction are generally:
A.
Freely moving throughout the material
B.
Tightly bound within atoms
C.
Absent from every atom
D.
Moving only in circular paths outside the material
Correct Answer:
Tightly bound within atoms
Explanation:
The electrons in an insulator are tightly bound to their atoms, so they are not available to carry current freely.
8. Which description correctly identifies an insulator?
A.
A substance that opposes the movement of electric charges
B.
A substance that supplies unlimited electric charges
C.
A substance with freely moving electrons everywhere
D.
A substance that conducts current perfectly
Correct Answer:
A substance that opposes the movement of electric charges
Explanation:
An insulator opposes the movement of electric charges because it has high resistance and very few free carriers.
9. The main reason an insulator does not conduct electricity well is that it has:
A.
A large number of free electrons
B.
A small number of free charge carriers
C.
A very low resistance
D.
A continuous supply of electric current
Correct Answer:
A small number of free charge carriers
Explanation:
The small number of free charge carriers in an insulator makes the conduction of electric current very difficult.
10. Which phrase is most suitable as a simple definition of an insulator?
A.
A material that conducts electricity efficiently
B.
A material that resists the flow of electricity
C.
A material that converts electricity into light only
D.
A material that always becomes charged positively
Correct Answer:
A material that resists the flow of electricity
Explanation:
An insulator is a material that resists the flow of electricity because its charge carriers are not free to move.
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