Electrical Engineering Materials Assessment

What is the main function of insulators in electrical systems?

• To store electric charge for later use.

• To convert electrical energy into heat.

• To enhance the flow of electric current.

• The main function of insulators in electrical systems is to prevent the flow of electric current.

What defines a semiconductor material?

• A substance that has no electrical conductivity at all.

• A material that conducts electricity perfectly without resistance.

• A material that has electrical conductivity between that of a conductor and an insulator, often used in electronic components.

• A type of metal that is used exclusively for wiring.

How does temperature affect the conductivity of semiconductors?

• Temperature increases conductivity in semiconductors.

• Temperature only affects metals, not semiconductors.

• Temperature has no effect on conductivity in semiconductors.

• Higher temperatures decrease conductivity in semiconductors.

What are the two types of semiconductor materials?

• Intrinsic and extrinsic semiconductors

• Conductive and non-conductive materials

• Organic and inorganic semiconductors

• Metallic and dielectric materials

Explain the term 'dielectric strength'.

• Dielectric strength refers to the ability of a conductor to carry current.

• Dielectric strength is the minimum temperature at which a material can operate safely.

• Dielectric strength is the resistance of a material to thermal expansion.

• Dielectric strength is the maximum electric field a dielectric material can withstand without electrical breakdown.

What is the role of dielectric materials in capacitors?

• Dielectric materials increase capacitance and improve insulation in capacitors.

• Dielectric materials are used to conduct electricity in capacitors.

• Dielectric materials decrease capacitance and reduce insulation in capacitors.

• Dielectric materials have no effect on the performance of capacitors.

Name a common dielectric material used in electronics.

• Glass

• Copper

• Silicon

• Polyethylene

How do conductors differ from semiconductors in terms of electron movement?

• Conductors and semiconductors have identical electron movement properties.

• Both conductors and semiconductors allow restricted electron movement.

• Conductors allow free electron movement, while semiconductors have restricted electron movement that can be modified.

• Conductors have no electron movement, while semiconductors allow free movement.

What is the significance of doping in semiconductor materials?

• Doping reduces the thermal conductivity of semiconductor materials.

• Doping is used to create insulators in electronic devices.

• Doping has no effect on the electrical properties of semiconductors.

• Doping is significant because it enhances the electrical conductivity of semiconductor materials, enabling the creation of p-type and n-type semiconductors essential for electronic devices.

Describe the impact of impurities on the conductivity of semiconductors.

• Impurities only affect the thermal properties of semiconductors.

• Impurities enhance conductivity by introducing charge carriers, but excessive impurities can reduce mobility and conductivity.

• All impurities decrease conductivity regardless of type.

• Impurities have no effect on conductivity.