ANS:B - Crimp and Bruge

There is no widely recognized formula or concept known as "Crimp and Bruge" in the context of hydraulic engineering or fluid mechanics, especially related to Manning's formula or rugosity coefficients. In Manning's formula, the rugosity coefficient (n) represents the roughness of the channel bed and walls, affecting the resistance to flow. Manning's formula is expressed as: V=1/n ​R ^2/3 ​S1/2​ Where:

• V is the velocity of flow,
• n is the rugosity coefficient,
• R is the hydraulic mean depth,
• S is the slope of the channel bed.

The value of the rugosity coefficient (n) varies depending on the characteristics of the channel, such as its roughness, material, and geometry. For example, a smooth concrete channel might have a lower n value compared to a natural earthen channel. However, the specific value of n=0.012 mentioned in your question is not typically associated with Manning's formula or any specific formula or concept in hydraulic engineering.