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Wattless Current
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Wattless Current.
In an ac circuit R = 0 Þ cosÆ = 0 so Pav = 0 i.e. in resistance less circuit the power consumed is zero. Such a circuit is called the wattless circuit and the current flowing is called the wattless current.
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The component of current which does not contribute to the average power dissipation is called wattless current
(i) The average of wattless component over one cycle is zero
(ii) Amplitude of wattless current = i0 sinÆ
and r.m.s. value of wattless current = irms sin Æ = (i0 /Ö2 ) sin Æ .
It is quadrature (90°) with voltage
Note : The component of ac which remains in phase with the alternating voltage is defined as the effective current. The peak value of effective current is i0 cosÆ and it's r.m.s. value is irms cos Æ = (i0/Ö2 ) cos Æ.
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