A transformer is used to step down the voltage from a 230 V outlet so that an appliance rated at 115 V may be used. The appliance is a constant power load, that is, it draws constant power as long as the voltage across it is near 115 V. The transformer has an impedance equal to 0.5 + j0.8 Ω referred to the high-voltage side. The appliance is consuming 1,800 W at 0.88 power factor lag. It was measured that the voltage across the load is 110 V. a.) What is the reactive power drawn by the appliance? b.) The voltage across the appliance is measured to be 110 V rms. Assuming that the appliance voltage is the reference phasor, what is the phasor current through the appliance? c.) What is the impedance of the transformer when referred to the low-voltage side?
A transformer is used to step down the voltage from a 230 V outlet so that an appliance rated at 115 V may be used. The appliance is a constant power load, that is, it draws constant power as long as the voltage across it is near 115 V. The transformer has an impedance equal to 0.5 + j0.8 Ω referred to the high-voltage side. The appliance is consuming 1,800 W at 0.88 power factor lag.
It was measured that the voltage across the load is 110 V.
a.) What is the reactive power drawn by the appliance?
b.) The voltage across the appliance is measured to be 110 V rms. Assuming that the appliance voltage is the reference phasor, what is the phasor current through the appliance?
c.) What is the impedance of the transformer when referred to the low-voltage side?
d.) What is the rms voltage across the supply?
e.) What is the real power lost in the transformer?
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