Moderate

The coefficient of viscosity for hot air is:

Correct answer: A. Greater than the coefficient of viscosity for cold air

  • A. Greater than the coefficient of viscosity for cold air
  • B. Smaller than the coefficient of viscosity for cold air
  • C. Same as the coefficient of viscosity for cold air
  • D. Increases or decreases depending on the external pressure

Explanation

For gases, viscosity increases with temperature because molecular momentum transfer rises with thermal speed; hence hot air has a larger viscosity than cold air.

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