Minimum spacing between horizontal parallel reinforcement of different sizes, should not be less than

ANS:B - one diameter of thicker bar

The anchorage value of a hook is typically expressed as a multiple of the diameter (d) of the reinforcement bar. The anchorage value represents the length of the straight portion of the bar beyond the end of the hook, which is necessary to develop the required bond strength with the surrounding concrete. In general engineering practice, the anchorage value of a hook is commonly assumed to be sixteen times the diameter (d) of the reinforcement bar. This means that the straight portion of the bar beyond the end of the hook should be sixteen times the diameter (d). Therefore, the correct answer is: Anchorage value of hook=16d So, among the options provided, the correct answer is: 16d