In an AC circuit, the voltage E, current I, and impedance Z are related by the
\Formula E = I · Z
\Find the current in a circuit with voltage 14 – 8j volts and Impedance is 2 – 3j ohms.
E = I · Z
\Substitute E and Z values
\14 – 8j = i · (2 – 3j)
\Divide each side by (2 – 3j) \ \
\Multiply the numerator and denominator by the conjugate of the denominator
\2 – 3j. Conjugate of 2 – 3j is 2 + 3j.
\\
(Multiply the numerator using FOIL method)
(Using multiply formula:
)
(Evaluate powers:
) \ \
(Multiply:
)
(Multiply:
)
(Distributive property:
)
(Subtract:
)
(Substitute the imaginary unit value
)
\
\
(Product of two same signs is positive)
(Commutative property: a + b = b + a)
(Add: 28 + 24 = 52 and 4 + 9 = 13)
(Write standard division form:
)
(Divide:
)
The current is 4 + 2j amps.