Dear Noman
I am also Electrical Engineer and i opt both app math and physics..

you must keep app math inn.. but for physics you better read out syllabus and paper then decide..

however app math is perfect choice..

go for the same books as mentioned earlier by someone. only i prefer

for Differential and Partial portion only one book and that sufficient

Higher Engineering Mathematics by BS Grewal...

take care

wish you good luck
AwA