Are all of the solar energy intercepted by the earth arrive as oblique rays?

No, not all solar energy intercepted by the Earth arrives as oblique rays. Solar energy reaches the Earth in the form of parallel rays, but the angle at which these rays strike the surface varies based on the Earth's curvature and its axial tilt. This variation causes some regions to receive sunlight more directly (perpendicular rays) while others receive it at an angle (oblique rays). Consequently, the intensity of solar energy varies across different locations and times of the year.