For a solid, the coefficients of linear, superficial and cubical expansion are in the ratio
- A.1 : 2 : 3
- B.3 : 2 : 1
- C.1 : 1 : 1
- D.2 : 3 : 4
Correct answer
Explanation
The correct answer is A, one to two to three. If each length of a solid grows by a certain small fraction when it is heated, an area, which is the product of two lengths, grows by about twice that fraction, and a volume, the product of three lengths, by about three times. So the superficial coefficient is twice the linear and the cubical is three times the linear.
Option B reverses the order and would mean that a body expands least in volume, which is the opposite of what happens. Option C would be true only if area and volume did not depend on more than one length, which is not the case. Option D follows no rule at all. This ratio explains why gaps are left between rails and why a bimetallic strip of two metals with different linear coefficients bends when heated and works as a switch in a thermostat.
Read the full article: Heat and Thermodynamics: Laws, Latent Heat and Transfer
Practice Questions
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- A.Calorie
- B.Joule
- C.Kelvin
- D.Watt
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- A.0 degrees Celsius
- B.4 degrees Celsius
- C.100 degrees Celsius
- D.Minus 4 degrees Celsius
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- A.80 calories per gram
- B.540 calories per gram
- C.336 calories per gram
- D.2260 calories per gram
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- A.Conduction and convection
- B.Radiation only
- C.Conduction only
- D.Neither conduction nor convection
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- A.The conservation of energy
- B.The increase of entropy
- C.Thermal equilibrium
- D.The unattainability of absolute zero
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