Voltage across string = 57.74 kV 

(i) Voltage across top insulator = 8.00 kV 
    Voltage across second unit = 8.80 V 
    Voltage across third unit = 10.48 V 
    Voltage across fourth unit = 13.19 V 
    Voltage across fifth unit = 17.27 V 

(ii) String efficiency = 66.85 % 


