In the given arrangement, the reading of ammeter is same in each case when either `k_(1)` or `k_(2)` is closed. The reading of the ammeter is

Options

A. `(E_(1) - E_(2))/(R )`
B. `(E_(1) + E_(2))/(R )`
C. Date given is not sufficient
D. None of above

Answer

C

Explanation

(c ) If `K_(2)` is closed, the current read by ammter
`I = (E_(2) - V)/(R' + R)`
If `K_(1)` is open
`I = (E_(1) - V)/(R')`
The reading of ammter is same in both cases
`implies i= (E_(2) - V)/(R' + R) = (E_(1) - V)/(R') implies ((E_(2) - V) - (E_(1) - V))/((R' + R) - R')`
Hence reading of ammeter `(E_(1) - E_(2))/(R )`