Two alternative laboratory methods are available for measuring an unknown resistance X using a d.c. supply of 6V:
(i) Draw neat circuit diagrams for Method A and Method B, clearly showing the positions of the meters.
(ii) For each method, derive an expression for the resistance value that would be calculated by the student (XA for Method A and XB for Method B) in terms of X, RA, and RV.
(iii) If the true resistance is X=50Ω, compute the percentage error in the value obtained by each method. State which method yields the more accurate result and justify your choice.