Yes, it is true that the liquidity of a business firm is measured by its ability to pay its long-term obligations as they become due. Here, the longterm obligation means payment of principal amount on the due date and payment of interest on the regular basis.
For measuring the long term solvency of any business, we calculate the following ratio.
(i) Debt equity ratio
(ii) Proprietary ratio

(i) Inventory turnover ratio is a relationship between the cost of goods sold during a particular period of time and the cost of average inventory during a particular period. It is expressed in number of times.
(ii) Inventory turnover ratio indicates the number of times, the stock has been turned over during the period and evaluates the efficiency with which a firm is able to manage its inventory.

Ratio will increases as both the quick assets and current liabilities i.e., cash and creditors, will decreases by the same amount.

Turnover ratios show how efficiently assets or other items have been used to generate revenue from operations. They are also called as activity ratios or efficiency ratios.
The important turnover or activity ratios are:
(i) Inventory turnover ratio
(ii) Trade receivables turnover ratio
(iii) Trade payables turnover ratio
(iv) Fixed assets turnover ratio

Liquidity means capability of being converted into cash with ease. Liquidity ratios help to assess the ability of a business concern to meet its short term financial obligations. Liquidity ratios are also called as short term solvency ratios.