10 mm
15 mm
20 mm
25 mm
Answer is Right!
Answer is Wrong!
The correct answer is: A. 10 mm.
The minimum thickness of the cover at the end of a reinforcing bar should not be less than twice the diameter of the bar subject to a minimum of 10 mm. This is to ensure that the concrete has enough cover to protect the bar from corrosion and to provide adequate bond between the bar and the concrete.
Option B is incorrect because it is the maximum thickness of the cover, not the minimum.
Option C is incorrect because it is the diameter of the bar, not the minimum thickness of the cover.
Option D is incorrect because it is the maximum diameter of the bar, not the minimum thickness of the cover.