The sudden bursting of an inflated tyre is an example of which kind of process?
- A.Isothermal
- B.Adiabatic
- C.Isobaric
- D.Isochoric
Correct answer
Explanation
The correct answer is B, adiabatic. An adiabatic change is one in which no heat is exchanged with the surroundings. The bursting of a tyre happens so quickly that the escaping air has no time to take in or give out heat; it does work in expanding, its internal energy falls and it therefore cools, which is why the escaping air feels cold.
Option A, isothermal, is a change at constant temperature, which requires the process to be slow enough for heat to flow in or out and keep the temperature fixed. Option C, isobaric, is a change at constant pressure, such as the heating of a gas under a freely moving piston. Option D, isochoric, is a change at constant volume, such as heating a gas in a rigid closed vessel. The rise of moist air that forms cloud is another everyday adiabatic process.
Read the full article: Heat and Thermodynamics: Laws, Latent Heat and Transfer
Practice Questions
View allThe SI unit of heat is the
- A.Calorie
- B.Joule
- C.Kelvin
- D.Watt
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Heat is a form of energy in transit, so it is measured in the same unit as work and energy, the joule, which is one newton metre.
Read the full explanation →Water has its maximum density at a temperature of
- A.0 degrees Celsius
- B.4 degrees Celsius
- C.100 degrees Celsius
- D.Minus 4 degrees Celsius
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Water behaves abnormally between zero and four degrees: it contracts as it is heated in that range and expands again above four degrees, so the same mass occupies its least volume, and therefore has its greatest density, at four degrees Celsius.
Read the full explanation →The latent heat of vaporisation of water is about
- A.80 calories per gram
- B.540 calories per gram
- C.336 calories per gram
- D.2260 calories per gram
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This is the heat that one gram of water at a hundred degrees Celsius must absorb to become steam at the same temperature, with no rise in temperature at all; the same quantity is released when steam condenses back to water.
Read the full explanation →In a vacuum flask, the vacuum between the two walls prevents heat transfer mainly by
- A.Conduction and convection
- B.Radiation only
- C.Conduction only
- D.Neither conduction nor convection
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Both of these modes need matter: conduction passes energy from particle to particle and convection carries it by the movement of a fluid.
Read the full explanation →The first law of thermodynamics is essentially a statement of
- A.The conservation of energy
- B.The increase of entropy
- C.Thermal equilibrium
- D.The unattainability of absolute zero
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The first law says that the heat supplied to a system is equal to the increase in its internal energy plus the external work it does.
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