Question

if $i_t = 0.00639$ a, $i_2 = 0.00139$ a, $i_3 = 0.00154$ a, $i_4 = 0.00115$ a, then $i_1 = \square$ a.

Explanation:

Step1: Recall the formula for total current in parallel circuits

In a parallel circuit, the total current \( I_T \) is the sum of the individual branch currents. So, \( I_T = I_1 + I_2 + I_3 + I_4 \). We can rearrange this formula to solve for \( I_1 \): \( I_1 = I_T - I_2 - I_3 - I_4 \).

Step2: Substitute the given values

Substitute \( I_T = 0.00639 \, \text{A} \), \( I_2 = 0.00139 \, \text{A} \), \( I_3 = 0.00154 \, \text{A} \), and \( I_4 = 0.00115 \, \text{A} \) into the formula:
\[

$$\begin{align*} I_1 &= 0.00639 - 0.00139 - 0.00154 - 0.00115 \\ &= (0.00639 - 0.00139) - 0.00154 - 0.00115 \\ &= 0.005 - 0.00154 - 0.00115 \\ &= (0.005 - 0.00154) - 0.00115 \\ &= 0.00346 - 0.00115 \\ &= 0.00231 \end{align*}$$

\]

Answer:

\( 0.00231 \)