A doubt in udit

If an auditor is not able to obtain any audit evidence, he is not able to form any opinion.  In this case he gives an disclaimer of opinion.  for instance if the auditor is unable to verify the Register of Investments due to the reason that it has got destroyed, then in this case he is not able to get any audit evidence regards the details of investors.  Hence in such case he gives an disclaimer.

when an auditor is able to verify the evidence, but he is not satisfied with the procedure adopted by the company then in sycg case ge guves ab qualified opinion.  For instance if the company is liable to pay Income-Tax, but it has not made any provision for Income-Tax in it's books, then in such case the profits of the copmany are overstated.  In such cse the auditor gives an qualified opinion, stating that the No Provision of I-T has been made by the compan in the books of accounts.

if auditor scope is limited and it has pervasive impact then auditor issues disclaimer of opinion.

if it has limited impact and even auditor dis agrees with management and it is not material then qualified opinion is expressed.