The relationship between voltage, [tex]E[/tex], current, [tex]I[/tex], and resistance, [tex]Z[/tex], is given by the equation [tex]E=IZ[/tex].

If a circuit has a current [tex]I=3+i[/tex] and a resistance [tex]Z=2-i[/tex], what is the voltage of the circuit?

A. [tex]4 - i[/tex]
B. [tex]4 + i[/tex]
C. [tex]8 + i[/tex]
D. [tex]8 + 7i[/tex]



Answer :

Sure, let's work through this problem step-by-step.

1. Identify the given current [tex]\(I\)[/tex]:
[tex]\[ I = 3 + 2 \][/tex]
Here, the current [tex]\(I\)[/tex] is initially given as [tex]\(3 + 2\)[/tex].

2. Calculate the resistance [tex]\(Z\)[/tex] using the given relationship:
[tex]\[ Z = 2 - I \][/tex]
Substituting the given value of [tex]\(I\)[/tex]:
[tex]\[ Z = 2 - (3 + 2) = 2 - 5 = -3 \][/tex]
So, the resistance [tex]\(Z\)[/tex] is [tex]\(-3\)[/tex].

3. Calculate the voltage [tex]\(E\)[/tex] using the formula [tex]\(E = I \cdot Z\)[/tex]:
Substitute the calculated values of [tex]\(I\)[/tex] and [tex]\(Z\)[/tex]:
[tex]\[ E = (3 + 2) \cdot (-3) \][/tex]

4. Express [tex]\(I\)[/tex] in terms of its real and imaginary parts (since we're given [tex]\(I\)[/tex] to be [tex]\(3 + 2\)[/tex], where 2 is understood to be the imaginary part here):
[tex]\[ I = 5 \text{ (no imaginary part since it simplifies to a real number)} \][/tex]

5. Calculate the voltage [tex]\(E\)[/tex], now as the product of real and imaginary parts:
For the real part:
[tex]\[ E_{\text{real}} = 5 \cdot (-3) = -15 \][/tex]
For the imaginary part:
[tex]\[ E_{\text{imag}} = 0 \text{ (since there is no imaginary part in \(I\))} \][/tex]

6. Combine the results:
[tex]\[ E = -15 + 0j \][/tex]

Thus, the voltage [tex]\(E\)[/tex] is [tex]\(-15 + 0j\)[/tex], which is simply [tex]\(-15\)[/tex] when considering only the real number scenario. No imaginary part is present here.

So, the answer to the question is:
[tex]\[ \text{The voltage of the circuit is } -15 \][/tex]