Low sun angles result in reduced solar energy because:

Solar energy is a form of renewable energy that is harnessed using the technology of the photovoltaic cells. These cells are composed of semiconductors. When the light from the sun hits the semiconductor, the energy from the light particles, or photons, cause the electrons in the semiconductor to be 'excited'. When the electron moves across the semiconductor platforms, the electron flows, thus creating electricity.

Therefore, as much as possible, you want to capture all of the sun's light. This can be achieved when the Sun is high up the sky. But if there is low sun angle, then the concentration of the sun's energy that strike the PV cells would be lesser. 

Answer;

hot magma rises and pushes up toward the lithosphere, and as it cools it cycles back down toward the core to be heated again.

explanation; convection currents are the circular pathways taken by a fluid that enhances heat transfer by the process known as convection which occurs in fluids.convection currents transfer heat from one place to another by mass motion of a fluid. earth mantle is in a semi-liquid state and behaves like any other fluid, rising up from the bottom of the mantle after becoming hotter and less dense from heat of the earth's core, as the rock loses heat into the earth's crust it becomes cooler and more dense, then sinking back down to the core, then repeating the cycle.

Because its not moving at that time hope u understand