Multiple choice general knowledge science & technology Planck's constant is represented by which letter g c p h Reveal answer Fill a bubble to check yourself D Correct answer Explanation Planck's constant (h ≈ 6.626 × 10⁻³⁴ J·s) is a fundamental constant in quantum mechanics, relating the energy of a photon to its frequency (E = hf). The symbols g (gravity), c (speed of light), and p (momentum) represent other physical quantities.