Question

Ratio us/uk is [us--------->coefficient of static friction;uk------------->coefficient of kinetic friction ]

Answer 1

Answer :- $1 \leq \bold{\frac{\mu_s}{\mu_k}} \leq 2$

Exaplantion :- As you know, static friction is the friction that exists between two stationary objects and the surface on which it's resting while kinetic friction is the friction that exists between two objects moving relative to each other. And we also know for same normal reaction static friction is higher than kinetic friction.
It means coefficient of static friction is higher than coefficient of kinetic friction.

actually, Coefficient of static and kinetic friction are experimental values . I attached some experimental values of μs , μk and μs/μk .
Here you can see ratio of static friction and kinetic friction is always greater than 1 but less than 2.

[NOTE :- well , in attachment given μk/μs values . you should just take inverse of it ]