User: The greenhouse effect is a result of A. absorption and radiation of energy in the hydrosphere. B. consumption of fruits and vegetables that produce a biofuel. C. absorption and radiation of energy in the atmosphere.
A principal focus or focal point is a special focus: 1  For a lens, or a spherical or parabolic mirror, it is a point onto which collimated light parallel to the axis is focused. Since light can pass through a lens in either direction, a lens has two focal pointsâone on each side.
(Definition of âfocal pointâ from the Cambridge Advanced Learnerâs Dictionary & Thesaurus Â© Cambridge University Press) See all translations. /ËfoÊÂ·kÉl ËpÉÉªnt/. âº a focus or focus. âº art A focal point is the feature of a work of art that is the most interesting or important or the most strongly emphasized. (Definition of âfocal pointâ from the Cambridge Academic Content Dictionary Â© Cambridge University Press)