What is f major transposed down a major 2ND?

F major transposed down a major second becomes E major. In terms of notes, the F major scale consists of F, G, A, B♭, C, D, and E. When you transpose it down a major second, you shift each note down by two half steps, resulting in the E major scale: E, F♯, G♯, A, B, C♯, and D♯.