Indicate the correct statements:

 

Conductivity cells have cell constant values independent of the solution filled into the cell. The value of the cell constant depends on the length and the area of the electrodes.

$\text{ Cell constant }=\frac{\mathrm{l}}{\mathrm{A}}$

DC (direct current) is not used for measuring the resistance of a solution. A.C current is used for this purpose.

 Kohlrausch law is valid both for strong and weak electrolytes. However, the law is particularly valuable to calculate Λ_c ​
 of weak electrolytes.

The specific conductivity k decreases but the molar conductivity λ_M  and the equivalent conductivity λ_E  increase on dilution. This is because, on dilution, the total number of ions increases (due to an increase in the degree of dissociation) and the number of ions per unit volume decreases.