Question

Will the dilution of acid leads to decrease in ph value

Answer 1

With dilution,concentration of ions would decrease due to the increase of volume of the solution.
Hence the pH will increase. HCl is effectively fully dissociated in water, so is at its highest [H+] and lowest pH. Significant dilution will lower [H+] and raise the pH.
Remember that acid have a pH value less than 7?
So,Diluting an acid by adding more water increases the pH of the solution towards 7 making it less acidic.