Try E5
Play the open low E string and fret the A string at fret 2. You can add fret 2 of the D string as well: that is another E, an octave higher. Strum only the intended strings and gently mute the rest.
Move the shape
Place your index finger on fret 3 of the low E string (G) and your ring finger on fret 5 of the A string (D): G5. Slide the shape two frets higher for A5. The root-to-fifth spacing remains the same.
Is a power chord major?
No. Without a third, it has no major or minor quality, so we write E5 or G5 rather than E major or G minor.