Question

A 10 m long wire of resistance 20 Q is connected in series with a battery of emf 3 V and a resistance of 10 Ω. The potential gradient along the wire in V/m is ________.

Options

• 1.2

• 0.10

• 0.02

• 0.20

Answer 1

A 10 m long wire of resistance 20 Q is connected in series with a battery of emf 3 V and a resistance of 10 Ω. The potential gradient along the wire in V/m is 0.20.

Explanation:

The equivalent resistance of the circuit,

R_eq = 20 + 10 = 30 Ω

The current flowing through the wire,

i = `"V"/"R" = (3"V")/(30 Omega)` = 0.1 A

The potential gradient along the wire,

`= "Potential difference across 20 Ω"/"Length of 20 Ω wire"`

`= (0.1 xx 20 Omega)/(10 "m")`

= 0.20 V/m