See the electrical circuit shown in this figure. Which of the following equations is the correct equation for it ?

Options

A. `epsilon_(1) - (i_(1) + i_(2)) R - i_(1) r_(1) = 0`
B. `epsilon_(2) - i_(1) i_(1) R - epsilon_(1) - i_(1) r_(2) = 0`
C. `- epsilon_(2) - (i_(1) + i_(2)) R + i_(2) r_(2) = 0`
D. `epsilon_(1) - (i_(1) + i_(2)) R + i_(1) r_(1) = 0`

Answer

A

Explanation

(a) Apply Kirchhoff's second law, aslo called loop rule. The algebraic sum of the changes in potentail in complete transversal of a mesh (closed loop) is zero. Ie, `sum V = 0`
Here, `epsilon_(1) = (i_(1) + i_(2)) R - i_(1) r_(1) = 0`