I have an AA size Ni cd battery charger.
What happens when I used it to charge AA Alkaline battery?
How can I use AA size Ni cd battery charger(using some other components if required) to charge Alkaline battery??

 

You can't. Primary alkaline batteries are not designed to be recharged. Putting one in a NiCad charger is likely to be a dangerous undertaking. Read the wiki!

http://en.wikipedia.org/wiki/Recharging_alkaline_batteries

 

Alkaline batteries die for two reasons... the zinc anode - negative contact - dissolves to an open state, or the electrolyte paste in them dries out.
As Papabravo said, they cannot be recharged.

 

Some good advice from others.

That being said...

The only way to get the real answer to your question given the specific batteries you have and using the specific charger that you have is to try it. Then you can answer the first part
"I have an AA size Ni cd battery charger.
What happens when I used it to charge AA Alkaline battery?"

Please however do like your dentist does - Hide behind a suitable barrier to avoid any potential harm to yourself. And please take a video and instrument the experiment so data is available in case you do not survive.