In the last 100 years world sea level has risen by about 20 cm, or 0.2 m. Compared with this value, how much variation in sea level occurred generally from the year 1000 to the year 1900

the answer is neither ball has a charge.

because if they were both positively charged, they will repel each other.

if they were positively and negatively charged, they will seek.

elctricity and magnet is conversion to it

electric field is a function of 1/r^2

yes, the force per unit charge for a point charge is inverse square law.