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_2 r_2 -epsilon_1 - i_1 r_1 = 0`
C. `-epsilon_1 - (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

Current in `R : (i_1 + i_2)`
`A to A(path ABCDA)`
`V_A - i_1 r_1 + E_1 - (i_1 + i_2) R = V_A`
`E_1- (i_1 + i_2) R - i_1 r_1 = 0`.