...........(i) where m is the mass and K is the kinetic energy of the particle.When kinetic energy of the particle is increased to 16 times, then its de Broglie wavelength becomes, λ′=
h
√2m(16K)
=
1
4
λ
√2mk
=
λ
4
 (Using (i)) % change in the de Broglie wavelength