(i) Yes (ii) No

A hot wire ammeter only measures the root mean square(rms) value of alternating current. Hence, when it is used to measure a direct current, it will not show the fluctuating value of ac, but only show a constant current equal to the rms value of the current. Thus, it can be used to measure direct current having constant value. (Ans)

No, we do not need to change the graduations since the rms value of current is the same as the direct current.