Correct Answer - D
`hv=hv_(0)+(1)/(2)mv^(2)`
`(hc)/(lambda)=(hc)/(lambda_(0))+(1)/(2) mv^(2)`
`K.E. = hc ((lambda_(0)-lambda)/(lambdalambda_(0)))`
`((h^(2))/(2mlambda_(e)^(2)))=hc((lambda_(0)-lambda)/(lambdalambda_(0)))" "(thereforelambda=(h)/(sqrt(2mK.E)))`
`lambda_(e)^(2)=(lambdalambda_(0)h)/([lambda_(0)-lambda]2mc)`
`lambda_(e)=[(hlambdalambda_(0))/(2mc[lambda_(0)-lambda])]^((1)/(2))`