The Trigonometric Form of Complex Numbers Is Often Used by Electrical

Multiple Choice

The trigonometric form of complex numbers is often used by electrical engineers to describe the current I, voltage V, and impedance Z in electrical circuits with alternating current. Impedance is the opposition to the flow of current in a circuit. Most common electrical devices operate on 115-volt, alternating current. The relationship among these three quantities is $I = \frac { V } { Z }$ . The real part of I represents the actual current delivered to an electrical appliance in amps. Approximate this current when $V = 164 \operatorname { cis } 42 ^ { \circ }$ and $Z = 102 \operatorname { cis } 11 ^ { \circ }$ , and express the answer in rectangular form to two decimal places.

A) 2.76 amps
B) 1.33 amps
C) 1.23 amps
D) 1.38 amps
E) 1.45 amps