mark the correct alternative : The electric potential decreases from 120V to 80V as one moves on the X axis from x=-1cm to x=1cm . The electric field at the origin a) must be equal to 20V/cm b) may be equal to 20V/cm c) may be greater than 20V/cm d) may be greater than 20V/cm i think all a , b and c should be correct but the answer given in the book is b and c . it will be b or c depending upon whether the V vs x graph is concave or convex . and b option will be correct for straight line graph . what is incorrect in my approach ?