Answer:
A long lever with the fulcrum as close as possible to the load
Explanation:
If F be the effort , W be the weight , L₁ be the distance of load from fulcrum and L₂ be the distance of effort from the fulcrum ,
Taking moment of force about the fulcrum , we have
W x L₁ = F x L₂
F = W x ( L₁ / L₂ )
F will be minimum when L₁ will be minimum .
Hence fulcrum should be as close as possible to the load.
Answer: (3) ppm
Explanation: Concentration is defined as the amount of solute dissolved in a known amount of the solvent or a solution.
Parts per million (ppm) is used to express the concentration when a very small quantity of solute is present in a large quantity of the solution. It is defined as the mass of solute present in one milion
parts by mass of the solution.

L/s is used to express flow rate.
J/g is used to express energy per unit mass.
kPa is used to express pressure.