In a potentiometer experiment two cells of e.m.f. E and E are used in series and in conjunction and the balancing length is found to be 58 cm of the wire. If the olarity of E is reversed, then the balancing length becomes 29 cm . The ratio `(E_(1))/(E_(2))` of the e.m.f. of the two cells is

Options

A. `1:1`
B. `2:1`
C. `3:1`
D. `4:1`

Answer

C

Explanation

`(E_(1) + E_(2))/(E_(1) - E_(2)) = 58/29`
`rArr E_(1) + E_(2) = 2E_(1) - 2E_(2)`
`rArr E_(1) = 3E_(2) rArr E_(1)/E_(2) = 3`