Question

The length of a potentiometer wire is L. A cell of e.m.f E is balanced at length L/3 from the positive end of the wire. If the length of wire increases by L/2, then the same cell will give balance point at length ____________.

Options

• 2L/3

• L/2

• L/6

• 4L/3

Answer 1

The length of a potentiometer wire is L. A cell of e.m.f E is balanced at length L/3 from the positive end of the wire. If the length of wire increases by L/2, then the same cell will give balance point at length L/2.

Explanation:

`"E" = "V"/"L" xx "L"/3 Rightarrow "E" = "V"/(3"L"//2) xx "x"`

`therefore "V"/"L" xx "L"/3`

` = "V"/(3"L"//2) xx "x" Rightarrow "x"`

` = "L"/2`