gopi

Well, inter pass allows you to travel as far as the furthest Tube station on the Northern Line, or you could choose to just sit in a tube train on the Circle Line and travel round and round all day, taking in such destinations as Baker Street (Sherlock Holmes), Paddington (of Bear fame), Notting Hill, South Kensington (very posh), Victoria (gawd bless 'er), Westminster (Big Ben), Barbican and the Embankment, where Cleopatra's Needle is located.
Mind you, you won't be able to see any of these as you'll be stuck underground, going round and round.
Hope this helps.

I bet this is about the HAAD exam.