How is charge separation achieved in crystalline silicon, amorphous silicon and polymer solar cell.

Explain why the aperture of the spherical mirror should be small compared to the radius of curvature of the mirror.

Juan created a chart to him study for a test. which headings best complete the chart? x: transparent objects y: opaque objects x: opaque objects y: transparent objects x: high frequency waves y: low frequency waves x: low frequency waves y: high frequency waves

What causes the development of most clouds and precipitation in the atmosphere?