Three batteries having emfs and internal resistances as shown in figure are connected across a resistor of `2Omega`. The reading of ammeter is

Options

A. 1A
B. 1.5A
C. 2A
D. 2.5A

Answer

A

Explanation

Use `(E_(eq))/(R_(eq)) = E_1/R_1+E_2/R_2+E_3/R_3+…..`
The circuit can be redrawn as

`1/r_(eq) = 1/2+1/2+1/1`
`r_(eq) = 1/2 Omega`
`(E_(eq))/(1/2) = 10/2+10/2-5/1`
`E_(eq) = 10/4 = 2.5 V`
`i=(2.5)/(2.5) = 1A`