16 - 20 Physics SBAs for the Primary FRCA
Question 16
With regards to electricity, which of the following is true?
- Electrons will only pass between atoms in the presence of a voltage
- Thermistors are electrical insulators
- Diodes are semiconductors
- Atoms in semiconductors bind their electrons more tightly than in insulators
- A current requires a flow of electrons
Answer
- Diodes are semiconductors
As are thermistors.
Electrons will pass between atoms in the presence of a voltage or changing magnetic field.
Atoms within insulators bind their electrons the most strongly, followed by semi conductors, and conductors have very loosely bound electrons.
A current requires a flow of charge, which can be carried by electrons or positive ions.