A helium atom and hydrogen molecule are moving with same velocity. Ratio of Debroglie wavelength of hydrogen molecule to that of helium atom will be

Debroglie equation ;λ=hmv;‘h’ is a constant and ‘v’ is given as constant for both the particles; λ1λ2=m2m1; MW of hydrogen=2 u; Weight of hydrogen molecule=2×1.66×10-24g; AW of helium=4 u; Weight of helium atom=4×1.66×10-24g; λH2λHe=mHemH2; λH2λHe=42=21;