Physics Grade 10 Feb Assessment

A steel rod of length 2.00 m at 20°C is heated to 100°C and its length becomes 2.0020 m. The coefficient of linear expansion, α, is approximately

• 1.25 × 10⁻⁵ °C⁻¹

• 2.50 × 10⁻⁵ °C⁻¹

• 1.00 × 10⁻⁵ °C⁻¹

• 2.00 × 10⁻⁵ °C⁻¹

A flat metal sheet has an initial area of 1.00 m² at 20°C. When heated to 120°C its area becomes 1.00012 m². The coefficient of surface (area) expansion, β, is approximately

• 1.20 × 10⁻⁶ °C⁻¹

• 2.40 × 10⁻⁶ °C⁻¹

• 1.20 × 10⁻⁵ °C⁻¹

• 2.00 × 10⁻⁶ °C⁻¹

A cube of metal with a side length of 0.10 m increases its volume by 0.30% when heated by 100°C. The coefficient of volume expansion, γ, is approximately

• 3.0 × 10⁻⁵ °C⁻¹

• 1.0 × 10⁻⁵ °C⁻¹

• 3.0 × 10⁻⁴ °C⁻¹

• 1.0 × 10⁻⁴ °C⁻¹

For many solids, the coefficient of volume expansion is approximately three times the coefficient of linear expansion. If α = 1.2 × 10⁻⁵ °C⁻¹ for copper, then γ is about

• 3.6 × 10⁻⁵ °C⁻¹

• 4.0 × 10⁻⁵ °C⁻¹

• 3.6 × 10⁻⁵ °C⁻¹

• 3.0 × 10⁻⁵ °C⁻¹

A brass rod of length 1.50 m expands by 1.8 mm when its temperature increases by 80°C. Its coefficient of linear expansion is approximately

• 1.50 × 10⁻⁵ °C⁻¹

• 1.50 × 10⁻⁴ °C⁻¹

• 1.50 × 10⁻⁶ °C⁻¹

• 2.25 × 10⁻⁵ °C⁻¹

A glass container (assumed isotropic) has an initial area of 0.80 m² at 25°C. After heating to 125°C, the area becomes 0.80096 m². The fractional change in area per °C is approximately

• 9.6 × 10⁻⁶ °C⁻¹

• 1.2 × 10⁻⁵ °C⁻¹

• 2.4 × 10⁻⁵ °C⁻¹

• 9.6 × 10⁻⁷ °C⁻¹

A metal rod with α = 1.0 × 10⁻⁵ °C⁻¹ and length L = 1.00 m at 0°C is heated to 100°C. Its final length is approximately

• 1.0010 m

• 1.0100 m

• 1.0001 m

• 1.1000 m

The fractional change in length for a solid is given by ΔL/(LΔT). If a material shows ΔL/(LΔT) = 2.5 × 10⁻⁵ °C⁻¹, then its percentage increase in length per 100°C is approximately

• 0.25%

• 0.025%

• 2.5%

• 0.0025%

A steel beam 10.0 m long (α = 1.2 × 10⁻⁵ °C⁻¹) is heated by 150°C. Its length increases by roughly

• 0.018 m

• 0.0180 m

• 0.18 m

• 1.8 m

A material with a known coefficient of linear expansion of 2.0 × 10⁻⁵ °C⁻¹ experiences an increase in length of 0.50 mm when its temperature rises by 50°C. Its original length is approximately

• 0.50 m

• 1.0 m

• 2.5 m

• 5.0 m