I had observed that in Chemistry Work done by the system is Negative...., Where as in Physics it it Positive. Please explain which is correct?

@ ramya 
this is one of the brilliant ques , that is beacuse chemistry and phy are dealing with diffrent thing ., 
in chemistry we want to know how usefull a chemical is , . therefore , if it does work , then it loses energy inside it . that makes it less usefull . therefore , work done by chemical is -ve . 
in physics , we check how usefull a system is . the measure of usefullness of a system is besically how much energy it can supply us , the more work it does , the more energy it gives us . 
therefore , work is +ve in physics . 
phy is abt what we can do with stuff , and in chemi what the stuff can do .. 
HOPE U UNDERSTOOD THAT . 
ALL THE BEST ..