The expected answers were:
(a) Any two correct advantages  of the moving- coil instrument

 

• high sensitivity
• uniform scale
• not affected by  external magnetic field
• can be used as a multi-range instrument.

(b)(i)   

 

 

 

Same voltage across AB i.e.
20   x   0.010   =  1.990X
       X  =  20 x 0.010
                
                    1.990

       X  =  0.1Ω

 

 

 

 

 

 

From the diagram,
100  =  Vx + V20Ω
100 = 0.010X + 20 x 0.010
          0.010X  =  100 – 0.2
          X  =  99.8
                 0.010
          X  = 9980Ω
                                                                                                                        240
This question was on measuring instruments.  Part (a) was attempted by many candidates and scored high marks in it.
Candidates’ performance in part (b) was not as good as in part (a).