65) What is the material used inside the breather to prevent moisture entering the transformer ?

66) Efficiency of transformers is determined by knowing its input and output power. Unit of power used for this purpose is kVA/kW. What is the unit used for input and output when calculating the all day efficiency ?

67) The transformer used in conjunction with voltmeter is called a potential transformer. The standard rating of secondary of potential transformer is :

68) Secondary of a current transformer will have :

69) If the current rating of the installation is high, a current transformer is used in the energy meter circuit. If a current transformer of 100A/5A is connected with an energy meter, the multiplying factor for the recorded energy is