Question

A potentiometer wire has length L For given cell of emf E, the balancing length is `"L"/3` from 3 the positive end of the wire. If the length of the potentiometer wire is increased by 50%, then for the same cell, the balance point is obtained at length.

Options

• `"L"/2`from positive end

• `"L"/5`from positive end

• `"L"/3`from positive end

• `"L"/4`from positive end

Answer 1

`"L"/2`from positive end

Explanation:

For cell of emf E balancing length

`= "L"/3 = 1/3 xx "L"`(length of wire)

Increased length of wire = `"L" + "L"/2 = "3L"/2`

Since, the cell is the same, therefore the new balancing length = `1/3` (new increased length)

`= 1/3 xx 3/2 "L"`

`= "L"/2`

Therefore, for the same cell the balance point will be as length `"L"/2` from positive end.