Fig. shows a potentiometer circuit to determine

the unknown e.m.f. E. When the jockey makes contact at point A, the deflection is towards left. On moving the jockey from A to B, the deflection always remains towards left but goes on decreasing. This means that

• A

  the unknown e.m.f. is wrongly connected

• B

  the main potentiometer battery is wrongly connected

• C

  the unknown e.m.f. is less than the battery e.m.f.

• D

  the unknown e.m.f. is great$ than the battery e.m.f