In the following figure, electric field at y axis will be maximum at y=?

Explanation:

As we know that electric field due to each charge at any given height y due to the point charges is given by

now we know that horizontal component of electric field due to each charge will cancel out while vertical component will be added due to both

So here we can say

now we know that for maximum value of Electric field

after solving this we will have

6 cos 34, 6 sin 34 trig

what experimental evidence led scientists to change from the previous model to this one?

a few of the positive particles aimed at a gold foil seemed to bounce back.

the colors of light emitted from heated atoms had very specific energies.

experiments with water vapor showed that elements combine in specific proportions.

cathode rays were bent in the same way whenever a magnet was brought near them.