Please suggest me which the law have best applications in our daily life.and tell me which law I should choose for poster presentation.And laws must be related to electrical department?

dear pooja 
you can choose kirchoff law , and it have a wide range of application in every electrical circuits , for example in your household circuits , 
in any circuit presentation , if there will be parallel and series combination , and more than 5-6 resistance are present , in that case u have to apply kirchoff law for easy calculation to find out the unknown quantity . 
so, that will be better for poster presentation . 
HOPE IT CLEARS 
REGARDS