SEMI CONDUCTORS 1

Multiple Choice

Which of the following materials is most likely to be a conductor?

• Plastic

• Wood

• Copper

• Rubber

Open Ended

Why is it important to understand the differences between conductors and insulators in the study of basic electronics?

Multiple Choice

What is the definition of a semiconductor?

• A material with high electric conductivity like metals

• A material with low electric conductivity like insulators

• A material with electric conductivity intermediate between that of a pure metal and a good insulator

• A material that does not conduct electricity at all

Multiple Choice

Which of the following is NOT a semiconductor?

• Silicon

• Germanium

• Gallium Arsenide

• Copper

Open Ended

Describe the difference in electric conductivity between metals, semiconductors, and insulators.

Multiple Select

Which of the following are examples of semiconductors?

• Copper

• Silicon

• Germanium

• Iron

Fill in the Blanks

The semiconductor used in solar cells is

Multiple Choice

Which element shown in the diagram has four valence electrons and is commonly used in semiconductors?

• Copper

• Silicon

• Gold

• Iron

Open Ended

Describe the crystalline structure of semiconductors and its significance in their electrical properties.

Multiple Choice

Which type of bond exists in semiconductors?

• Ionic

• Metallic

• Electrovalent

• Covalent

Fill in the Blanks

At room temperature, thermal energy can liberate a valence electron in a semiconductor, creating a

in its place.

Multiple Choice

Current in a semiconductor is carried by which two types of carriers?

• Free electrons and ions

• Free electrons and holes

• Holes and protons

• Electrons and neutrons

Open Ended

Explain how the movement of electrons leads to the formation of holes in a semiconductor.

Multiple Choice

What creates electron-hole pairs in a pure semiconductor?

• Movement of valence electrons

• Movement of ions

• Addition of impurities

• Application of voltage

Open Ended

Describe the relationship between electrons and holes in a pure semiconductor and how they contribute to its electrical properties.

Multiple Choice

In semi-conductors, the carriers of current at room temperature are

• electrons only

• electrons and holes

• holes only

• electrons and ions

Fill in the Blanks

The major difference between a pure semiconductor and a pure metal is that

increases with temperature for metals, but decreases for semiconductors.

Multiple Select

Select all the ways in which the conductivity of a semiconductor can be increased.

• Increase in temperature

• Addition of impurity (doping)

• Application of magnetic field

• Presence of light of proper wavelength

Multiple Choice

Which of the following elements can be used as a pentavalent impurity to produce N-type semiconductors?

• Boron

• Phosphorus

• Gallium

• Aluminum

Multiple Choice

What is the difference between intrinsic and extrinsic semiconductors?

• Intrinsic semiconductors have impurities, extrinsic do not.

• Intrinsic semiconductors are pure, extrinsic have impurities or doping.

• Intrinsic semiconductors are metals, extrinsic are non-metals.

• Intrinsic semiconductors are always N-type, extrinsic are always P-type.

Open Ended

Describe the flow of electrons and holes in N-type and P-type materials when a voltage is applied.

Fill in the Blanks

In a P-type semiconductor, the majority carriers are

while the minority carriers are electrons.

Open Ended

Explain how the majority and minority charge carriers differ in N-type and P-type semiconductors.

Multiple Choice

Pure silicon can be converted to a p-type material by adding a controlled amount of

• pentavalent atoms

• hexavalent atoms

• tetravalent atoms

• trivalent atoms

Open Ended

Reflecting on what you learned about conductors and insulators, how do you think these materials are important in everyday electronic devices?

Multiple Choice

What is the main difference between conductors and insulators in terms of their electrical properties?

• Conductors allow the passage of electricity, insulators do not.

• Conductors have high electrical resistance, insulators have low resistance.

• Conductors are always metals, insulators are always plastics.

• Conductors are used for insulation, insulators are used for conduction.