If the rate of a reaction is equal to the rate constant,what is the order of the reaction?

Which of the following statements is true?

What is the correct relation between rate constant and half-life for a zero order reaction?

Give examples of zero order reactions.

For a general reaction $A \to B$,a plot of the concentration of $A$ versus time is given in the figure. Answer the following questions based on this graph:
$(i)$ What is the order of the reaction?
$(ii)$ What is the slope of the curve?
$(iii)$ What are the units of the rate constant?

For a reaction of $n^{th}$ order,the plot of $t_{1/2}$ versus initial concentration $[A]_0$ is a straight line. When the initial concentration is $2 \ mol \ L^{-1}$,the reaction takes $10 \ min$ to complete $50\%$. If the reaction takes $t \ min$ to complete $50\%$ when the initial concentration is $4 \ mol \ L^{-1}$,find $n$ and $t$ respectively.