The maximum value of hoop compression in a dome is given by (where, w = load per unit area of surface of dome R = radius of curvature d = thickness of dome) A. wR / 4d B. wR/2d C. wR/d D. 2wR/d

The correct answer is $\boxed{\text{B. }wR/2d}$.

The hoop compression in a dome is given by the following equation:

$$\sigma = \frac{wR}{2d}$$

where:

• $\sigma$ is the hoop compression
• $w$ is the load per unit area of surface of dome
• $R$ is the radius of curvature
• $d$ is the thickness of dome

The hoop compression is the maximum at the top of the dome, where the radius of curvature is the largest. The thickness of the dome is constant, so the hoop compression is proportional to the load per unit area of surface of the dome and inversely proportional to the thickness of the dome.

Option A is incorrect because it does not take into account the thickness of the dome. Option C is incorrect because it does not take into account the radius of curvature of the dome. Option D is incorrect because it is twice the correct value.