Question

A potentiometer wire is 10 m long and has resistance of 2`Omega`/m. It is connected in series with a battery of e.m.f 3 V and a resistance of 10 `Omega`. The potential gradient along the wire in V/m is ______.

Options

• 0.01

• 0.02

• 0.1

• 0.2

Answer 1

A potentiometer wire is 10 m long and has resistance of 2`Omega`/m. It is connected in series with a battery of e.m.f 3 V and a resistance of 10 `Omega`. The potential gradient along the wire in V/m is 0.2.

Explanation:

`"R"_"AB" = 2 xx 10 = 20 Omega`

I = `3/10 + 20 = 3/30 = 1/10 "A"`

So, V = `"I"  "R"_"AB" = 1/10 xx 20` = 2V

`"V"/"L" = 2/10 = 0.2 "V"/"m"`.