حرارتی طبیعیات

What is the maximum efficiency of an engine working between 600 K and 300 K?

• 1 50%
• 2 100%
• 3 75%
• 4 25%

The power radiated by a hot body is proportional to its absolute temperature raised to the power of:

• 1 3
• 2 2
• 3 4
• 4 1

A sealed rigid container of gas is heated from 27 degrees C to 327 degrees C. By what factor does the pressure change?

• 1 It doubles
• 2 It becomes 12 times larger
• 3 It does not change
• 4 It halves

A gas expands at a constant pressure of 1 x 10⁵ Pa, and its volume increases by 2 x 10⁻³ m³. How much work does it do?

• 1 2000 J
• 2 100 J
• 3 50 J
• 4 200 J

A 1 m metal rod lengthens by 1.2 mm when its temperature rises by 100 degrees C. What is its coefficient of linear expansion?

• 1 1.2 x 10⁻⁷ per degree C
• 2 1.2 x 10⁻³ per degree C
• 3 1.2 x 10⁻⁵ per degree C
• 4 1.2 x 10⁻² per degree C