Which of the following is NOT a physical property?

• Density

• Melting point

• Conductivity

• Softness

Answer explanation

Softness is a subjective measure of how a material feels, while density, melting point, and conductivity are quantifiable physical properties that can be measured objectively.

Which of the following is a mechanical property?

• Mass

• Toughness

• Conductivity

• Hardness

Answer explanation

Toughness and hardness are mechanical properties that describe a material's ability to withstand stress and deformation. Mass is a measure of quantity, while conductivity relates to electrical properties, not mechanical.

Which of the following properties would be most relevant for electrical engineers?

• Density

• Melting point

• Conductivity

• Coefficient of expansion

Answer explanation

Conductivity is crucial for electrical engineers as it measures a material's ability to conduct electricity, directly impacting circuit design and performance. The other properties are less relevant in this context.

Why is it important to understand the environment in high temperature applications?

• Because low temperature components require low thermal conductivity

• Because high temperature components require high thermal conductivity

• Because high temperature components require low thermal conductivity

• Because low temperature components require high thermal conductivity

Answer explanation

Understanding the environment in high temperature applications is crucial because high temperature components require high thermal conductivity to effectively dissipate heat and maintain performance, preventing failure.

What is the unit of measurement for mass in the density formula?

• Litres

• Kilograms

• Meters

• Celsius

Answer explanation

In the density formula, density is defined as mass divided by volume. The standard unit of mass is kilograms, making it the correct choice for this question. Litres measure volume, while meters and Celsius are unrelated.

What does the density formula calculate for solids, liquids, and gases?

• Temperature

• Mass per unit volume

• Speed

• Time

Answer explanation

The density formula calculates mass per unit volume, which applies to solids, liquids, and gases. This means it measures how much mass is contained in a given volume, making 'mass per unit volume' the correct choice.

If the density is 4 kg/m³ and the volume is 3 m³, what is the mass?

• 12 kg

• 7 kg

• 1.33 kg

• 0.75 kg

Answer explanation

To find the mass, use the formula: mass = density × volume. Here, mass = 4 kg/m³ × 3 m³ = 12 kg. Therefore, the correct answer is 12 kg.

If an object has a density of 0.25g/cm³ and a volume of 2,000cm³, what is its mass?

• 250g

• 400g

• 100g

• 500g

Answer explanation

To find mass, use the formula: mass = density × volume. Here, mass = 0.25g/cm³ × 2000cm³ = 500g. Thus, the correct answer is 500g.

What is the density of an object with a mass of 100g and a volume of 50cm³?

• 2g/cm³

• 0.5g/cm³

• 1g/cm³

• 4g/cm³

Answer explanation

Density is calculated using the formula: density = mass/volume. Here, density = 100g / 50cm³ = 2g/cm³. Therefore, the correct answer is 2g/cm³.

Specific heat capacity is an example of which type of property?

• Intensive property

• Extensive property

• Chemical property

• Physical property

Answer explanation

Specific heat capacity is an extensive property because it depends on the amount of substance present. Unlike intensive properties, which do not change with the quantity, extensive properties vary with the size or extent of the system.