Consider the following discharge measurement devices : 1. Cylindrical mouthpiece flowing full 2. Sharp-edged orifice 3. Convergent-divergent mouthpiece 4. Borda's re-entrant mouthpiece flowing free The correct sequence of increasing order of their discharge coefficients is

A square framework formed of uniform heavy rods of equal weight joined together is hung by one corner. A weight W is suspended from each of the three lower corners and the shape of the square is preserved .with the help of a light rod along the horizontal diagonal. The thrust of the light rod is