A particle having electric charge \( 3 \times 10^{-19} \; \text{C} \) and mass \( 6 \times 10^{-27} \; \text{kg} \) is accelerated by applying an electric potential of \( 1.21 \; \text{V} \). Wavelength of the matter wave associated with the particle is \( \alpha \times 10^{-12} \; \text{m} \). The value of \( \alpha \) is __________. (Take Planck’s constant \( = 6.6 \times 10^{-34} \; \text{J, s} \))
