Why do two isothermal curves not intersect each other?

Why two isotherms do not intercept each other.

In two circles , one circle passes through the centre O of the other circle and they intersect each other at the points A and B . A straight line passing through A intersect the circle passing through O at the point P and the circle with centre at O at the point R . BY joining P , B and R , B prove that PR= PB.

Can two different equipotential surfaces intersect each other?

The diagonals of the square ABCD intersect each other at O .Let OPbotAB is constructed. Prove that angleAOP =anglePBO

The two circles with centre X and Y intersect each other at the points A and B, A joined with the mid -point S of XY and the perpendicular on SA through the point A is drawn which intersect the two circles at the point P and Q .Prove that PA = AQ.

No two electric field lines can intersect each other. Why?

In the adjoining figure , two circles intersect each other at the points P and Q. If angleQAD=80^(@)andanglePDA=84^(@) , then find the value of angleQBCandangleBCP

Laxmi has drawn two circles which intersect each other at O externally. If PQ and RS be two parallel diameters of trhe circles, then prove that the points P, O and S are collinear.