Observe the circuit:

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The input sine voltage is $\"\"$ .

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Compare the function with $\"\"$ .

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Here $\"\"$ and $\"\"$ .

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$\"\"$ and $\"\"$ are in parallel.

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$\"\"$

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$\"\"$ can be written in polar form is $\"\"$ .

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$\"\"$ in polar form can be written as $\"\"$ .

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$\"\"$

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$\"\"$

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The sine voltage can be written as $\"\"$

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From (a): Total impedance $\"\"$ .

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Find the total current.

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$\"\"$

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$\"\"$

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Current in sinusoidal form, $\"\"$ .

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$\"\"$

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$\"\"$ .

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Substitute corresponding values in the expression $\"\"$ .

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$\"\"$

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Total current is $\"\"$ A.

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other when connected to a sinusoidal AC supply. In a pure ohmic resistor the voltage waveforms are “in-phase” with the current. In a pure inductance the voltage waveform “leads” the current by 90^o, giving us the expression of ELI. In a pure capacitance the voltage waveform “lags” the current by 90^o, giving us the expression of ICE.

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In RC circuits with sinusoidal AC supply,

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In a pure capacitance the voltage lags the current by 90^o.

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Phasor diagram for the voltage drop:

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$\"\"$

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