Two dc machines A and B, using the same conductor material, have armature circuit resistances of 0.4 Ω and 1.2 Ω respectively. Of the two machines,

• A.  A is bigger than B for the same voltage rating
• B.  A is bigger than B for the same current rating
• C.  both are of the same size for the same current rating
• D.  B is bigger than A for the same current rating

Answer: (A)