This question was fairly answered by most candidates.  However, many failed to get the trend of VL correctly, probably candidates did not make wire into a loop as demanded by the question.

The (b) part was not well attempted.  

In part (a) the candidates were expected to: 
         

measure and record to1 decimal place six value of l;

(iii)read and record to  1 decimal place six values of V_i ;  (Trend: as l increases,V_i increases then decreases)

(iv)read and record to 1 decimal place six values of V_R ;

  (v) evaluate  six values of ;    V_i      ;          
                                                       V_R                 

    (vi) record data in a composite table showing Ɩ, VƖ,   V_R,     and   V_l /  V_R ;                       
     (vii)       indicate the graph axes, select reasonable scales, plot six points;
 
     (viii)      draw a smooth curve through the points;

•  show and record the maximum value of M and the corresponding value of l;

(x)         state any two of the following precautions in acceptable form:
                  Ensured tight connections/ clean terminals

• Removed key after each reading
• Avoided parallax error in reading voltmeter
• Evidence of repeated readings
• Noted and corrected for zero error of voltmeter/meter rule.

(b)(i)    Effects of heating on the experimental results

• The constantan wire will increase in length (expand) and length of the loop increases. Consequently the value of Ɩ increases.                                                         
• The resistance of the wire increases                                                                

• To reduce the effect of heating, remove the key immediately after taking each reading