well,if we look at british history paper 2,2011.we come to know that its not sufficient preparation up to world war 2 as there were 3 questions from post ww2 era.You must prepare following topics
1-churchill 's personality and policies and his comparison with other post ww2 british prime ministers like Macmillion, Margaret Thatcher ,Tony Blair etc.
2-labour govt after ww2 ant its policies particularly regarding welfare state.
3-Suiz canal crisis and British role.
4-Cold War and British role.
5-British world position after ww2.
6-Margaret Thatcher and her policies.
7-British role in war on terror.