Question

heat transfer phenomena in conduction convection and radiation

Answer 1

in conduction, heat is transferred by the molecules when they vibrate about their mean positions. there is no actual movement of molecules.
In convection, the actual movement of molecules take place when heat is applied. There is a cyclic motion of molecules by which heat is transferred throughout the body. It is a bulk phenomenon.
In radiation there is no direct contact between the substances and one substance simply radiates heat energy, like solar energy.