A single phase transformer has 1000 turns on the primary and 200 turns on the secondary. The no load current is 3A at a power factor of 0.2 lag and the secondary current is 280A at a power factor of 0.8 lag. Neglect R2 and X2 calculate (1) Magnetizing component and loss component of no load current. (2) primary current (3) input power factor .Draw phasor diagram showing all the currents.
cos𝜑2=0.8 cos𝜑0=0.2 sin𝜑2=0.6 sin𝜑0=0.98
solve for horizontal and vertical components
𝐼1𝑠𝑖𝑛𝜑1=𝐼2𝑠𝑖𝑛𝜑2+𝐼0𝑠𝑖𝑛𝜑0 =(56×0.6)+(3×0.98) = 36.54A
tan𝜑1 `(36.54)/(45.4)`= 0.805
Power factor cos𝝋𝟏=𝒄𝒐𝒔𝟑𝟖°=𝟎.𝟕𝟖 lagging.