when we have to use UPF wattmeter and LPF wattmeter?
what is the difference between UPF and LPF wattmeter in
terms of construction?

Answer Posted / shoeb

my dear friend . UPF stands for unity power factor and LPF means low power factor . we have UPF or near UPF when we are dealing with capacitance and WE have LPF when we are dealing with inductance because in the case of capacitans powerfactor lead and in the case of inductance powerfactor will lag ..... this is the difference b/w UPF & LPF

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