<PAGE>
 
                                                                    Exhibit 12-B

                        Delmarva Power & Light Company

          Ratio of Earnings to Fixed Charges and Preferred Dividends
          ---------------------------------------------------------- 
                             (Dollars in Thousands)
                             ----------------------


<TABLE> 
<CAPTION> 
                                            1996        1995        1994        1993        1992      
                                          --------    --------    --------    --------    --------  
<S>                                       <C>         <C>         <C>         <C>         <C>         
                                                                                                     
Net income                                $116,187    $117,488    $108,310    $111,076    $ 98,526   
                                          --------    --------    --------    --------    --------
                                                                                                     
Income taxes                                78,340      75,540      67,613      67,102      54,834   
                                          --------    --------    --------    --------    --------
                                                                                                     
Fixed charges:                                                                                       
   Interest on long-term debt                                                                        
     including amortization of                                                                       
     discount, premium and                                                                           
     expense                                69,329      65,572      61,128      62,651      66,976   
   Other interest                           12,516      10,353       9,336       9,245       8,449   
   Preferred dividend require-
     ments of a subsidiary
     trust                                   1,390           -           -           -           -
                                          --------    --------    --------    --------    --------
     Total fixed charges                    83,235      75,925      70,464      71,896      75,425   
                                          --------    --------    --------    --------    --------
                                                                                                     
Nonutility capitalized interest               (311)       (304)       (256)       (246)       (231)  
                                          --------    --------    --------    --------    --------
                                                                                                     
Earnings before income taxes                                                                         
   and fixed charges                      $277,451    $268,649    $246,131    $249,828    $228,554   
                                          ========    ========    ========    ========    ========

Fixed charges                             $ 83,235    $ 75,925    $ 70,464    $ 71,896    $ 75,425

Preferred dividend requirements             14,961      16,185      15,948      14,803      15,785
                                          --------    --------    --------    --------    --------

                                          $ 98,196    $ 92,110    $ 86,412    $ 86,699    $ 91,210
                                          ========    ========    ========    ========    ========
                                                                                                     
Ratio of earnings to fixed charges
   and preferred dividends                    2.83        2.92        2.85        2.88        2.51   
</TABLE> 

For purposes of computing the ratio, earnings are net income plus income taxes
and fixed charges, less nonutility capitalized interest. Fixed charges consist
of interest on long- and short-term debt, amortization of debt discount,
premium, and expense, dividends on preferred securities of a subsidiary trust,
plus the interest factor associated with the Company's major leases, and one-
third of the remaining annual rentals. Preferred dividend requirements represent
annualized preferred dividend requirements multiplied by the ratio that pre-tax
income bears to net income.