A potentiometer has uniform potential gradient across it. Two cells connected in series $(i)$ to support each other and $(ii)$ to oppose each other are balanced over $6\,m$ and $2\,m$ respectively on the potentiometer wire. The $e.m.f.$’s of the cells are in the ratio of
  • A$1:2$
  • B$1:1$
  • C$3:1$
  • D$2:1$
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