The completed diagram is given below:
The part A is called primary coil. The part B is called secondary coil. The part drawn is called core. The material of core is soft iron.
(i) This transformer is step-down since it has more turns in primary coil than in secondary coil.
(ii) A step-up transformer has more turns in secondary coil as compared to that in primary coil, while a step-down transformer has more turns in primary coil as compared to that in secondary coil.
(iii) In a step-up transformer the wire in the primary coil is thicker as compared to that in secondary coil, while in a step down transformer the wire in secondary coil is thicker as compared to that in primary coil.