A particle of mass 1 mg has the same wavelength as an electron moving with a velocity of $3 \times 10^6\: ms^{-1}$. The velocity of particle is :

Question

$\begin {array} {1 1} (1)\;2.7 \times 10^{-21}ms^{-1} & \quad (2)\;2.7 \times 10^{-18}ms^{-1} \\ (3)\;9 \times 10^{-2}ms^{-1} & \quad (4)\;3 \times 10^{-31}ms^{-1} \end {array}$

 

(mass of electron $= 9.1 \times 10^{-31} kg)$