Question

The figure above shows the electric field around a positive charge. Where is the field strongest

Answer 1

The electric field, or any field such as magnetic field or gravitational field, is the strongest the closer we get to the source of the field. The concentration of field lines also increases closer to the object; these field lines are seen to be coming out of a positive charge. 
Therefore, the strongest electric field is at the point where the concentration of electric field lines is the highest.