Who first proposed the plum pudding model of the atom?

shivam, but if you're clever enough to be a physicist then surely you have the ability to work out that "Joseph John" can be abbreviated to "JJ". No? In case you get a question about Winnie-the-Pooh, the author's full name is Alan Alexander Milne even though he is commonly referred to as A. A. Milne. I hope that helps.

So why is this called the Plum Pudding model?

I was looking for J J Thompson and here the option has his full name, to every physics he has always been J J Thompson.