Thermal Properties of Matter

Q1.The normal human body temperature is 98.6°F. In Celsius, this is approximately:

• A36°C
• B37°C
• C38°C
• D40°C

Q2.A wall of area 10 m² and thickness 20 cm separates two rooms at 30°C and 10°C. If thermal conductivity K = 0.8 W/(m·K), the heat flow rate is:

• A800 W
• B80 W
• C8 W
• D8000 W

Q3.The Sun's surface temperature is approximately 5800 K. Using Wien's law (b = 2.9×10⁻³ m·K), the peak wavelength of solar radiation is:

• A500 nm
• B5000 nm
• C50 nm
• D5 μm

Q4.Water shows anomalous expansion between 0°C and 4°C. This means that in this range:

• AWater contracts on heating
• BWater expands on heating
• CWater density decreases from 0°C to 4°C
• DWater density increases from 0°C to 4°C

Q5.A metal rod expands by 0.5% when its temperature increases by 100°C. The coefficient of linear expansion is:

• A5×10⁻⁵/°C
• B5×10⁻⁴/°C
• C5×10⁻³/°C
• D5×10⁻⁶/°C