The basic wind speed is specified at a height ‘h’ above mean ground level in an open terrain. The value of ‘h’ is A. 10 m B. 20 m C. 25 m D. 50 m

The correct answer is: A. 10 m.

The basic wind speed is the wind speed at a height of 10 meters above mean ground level in an open terrain. It is used to calculate the wind loads on structures and other objects.

The basic wind speed is determined by the following factors:

• The location of the structure or object.
• The type of terrain.
• The height of the structure or object.
• The exposure of the structure or object.

The basic wind speed is typically specified in a building code or other regulation. It is important to use the correct basic wind speed when calculating wind loads on structures and other objects.

The other options are incorrect because they are not the standard height at which the basic wind speed is specified.