Question

The correct option is 2 but how to solve it ??​

Answer 1

Answer:

,

ANSWER IS option 2

Explanation:

By the formula ,

electric field due to infinite long wire at a distance R is ,

2k ( lamda) / R

where lamda = charge per unit length

= Q/L

where ,

Q is charge and L is length .

now suppose that we want to calculate the force on second wire due to first wire.

therefore we will consider charge of second wire and electric field of first wire .

FORCE = Q×E

but ,

E = 2K ( lamda 1) / R .

THEREFORE ,

F = 2K( lamda 1) ×Q/ R

But we have to calculate force per unit length, so dividing both the sides by 'L '

F / L = 2K(lamda1) ×Q/RL

BUT ,

Q/L = lamda 2 ( charge per unit length)

therefore final expression will be ,

F/L = 2K(lamda 1 ) ( lamda 2 ) / R

NOTE .

Q / L = lamda 2 ... not lamda 1 because we are considering charge of second wire and electric field of first wire.

hope it will help you .✌✌✌