A proton and an `alpha`- particle are accelerated through the same pontential difference. What is the ratio of their de-Broglie wavelengths.

Two charged particles carrying equal charge enter into a magnetic field region after being accelerated through the same potential difference. The particles describe circular paths of radii R_1 and R_2 respectively. If m_1 and m_2 are the masses of the particles then ((m_1)/m_2) is given by