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 Strengthening Skills •  Building Confidence

 Procedure This figure represents the simplest possible ac circuit--an ac voltage source connected to a single load. The source voltage is expressed with zero phase VTÐ0° V for the rectangular form VT +j0 V in rectangular form The load may be Purely resistive: Z1Ð0° W Purely inductive: Z1Ð+90° W Purely capacitive: Z1Ð-90° W Inductive with a resistive component: Z1Ðq where q does not equal 0°, +90° or -90° Capacitive with a resistive component: Z1Ð-q where q does not equal 0°, +90° or -90° The total impedance of the circuit is equal to  Z1: ZT = Z1 The total current is determined by Ohm's law: Examples Example 1 Given: Z1 = 50 W, VT = 12 V Find: ZT, IT Solution: ZT = Z1 ZT = 50Ð0° W IT = 0.24Ð0° A Note: This is a purely resistive circuit. Example 2 Given: Z1 = 24Ð90° W, VT = 12V Find: Find: ZT, IT Solution ZT = Z1 ZT = 24Ð90° W IT = 0.5Ð-90° A Note: This is a purely inductive circuit. Example 3 Given: Z1 = 10Ð-50° W, VT = 12 V Find: ZT, IT Solution ZT = Z1 ZT = 10Ð-50° W IT = 1.2Ð50°A Note: This is an RL circuit.