A long line of charge with uniform linear charge density λ1 is located on the x-axis and another long line of charge with uniform linear charge density λ2 is located on the y-axis with their centers crossing at the origin. In what direction is the electric field at point z = a on the positive z-axis if λ1 and λ2 are positive? A-) The positive z-direction
B-) All directions are possible parallel to the x-y plane
C-) The negative z-direction
D-) Halfway between the x-direction and the y-direction
C-) Cannot be determined

A.The positive z-direction

Explanation:

We are given that

Linear charge density of long line which is  located on the x-axis=

Linear charge density of another long line which is  located on the y-axis=

We have to find the direction of electric field at z=a on the positive z-axis if and are positive.

The direction of electric field  at z=a on the positive z-axis  is positive z-direction .

Because and are positive and the electric field is  applied away from the positive charge.

Hence, option A is true.

A.The positive z-direction

it is b. absorbs thermal energy