Hi Rana --
Generally, coin collectors and note collectors stay clear of each other. It's just one of those Hobby things. I know very little about collecting paper currency.
But, I know about eBay, and about the large collector base on eBay. Coins that sell on eBay almost always reach true market value. The same is probably true of notes like yours.
Here are two notes that sold on eBay recently. One is "raw" and one is graded by PMG. The "raw" one sold for $16 US dollars, which is about the value of yours. The PMG note sold for $126, due to the fact that it grades so high. Your note is in nice condition, but not as well preserved as the $126 note.
The date of issue of your note will be 1998 and not 1940.
50/1940 will be the law number under which all "paper money" or notes, are issued in Egypt.
You will also note that somebody wrote on your note with a pen which will lower the value to almost worthless to a collector.
An uncirculated note for sale at the following page for $0.69