As adjectives, graphic and graphic are equivalent. Graphic is also a noun, as in visual graphic, whereas graphical is only an adjective.

These are phrases where graphic is the conventionally used, others phrases where graphic is the norm. Therefore, it’s important to choose the correct word for a given situation. If you’re not familiar with a word, make sure you use the correct one.

Graphic arts,

graphic equalizer,
graphic novel,
graphic artist,
graphics card,
graphic designer
flowcharts are

graphical presentations, graphical user
interface interface.