about depreciation

For the tubelights which has been destroyed you must have charged it to P/L account when those were purchased, so you neednot make any entry for its loss due to fluctuation. But as regards new tube you may pass the entry as follows; Electrical Maintanance A/c. Dr. ..... To Cash/Bank A/c. ......

As there is no increase in capacity so treat those expenditure as revenue expenditure

BUT CAN I SHOWED BULBS , LIGHTS ETC AS FIXED ASSETS (FIXTURE & FITTINGS) OR NOT?

Give us a practical situation dude! You will get an answer. Don't come up with examples of capitalising tubelights and nuts...