Caulker joined the Bluebirds on a four-year contract on Wednesday evening after passing his medical, with Cardiff understood to have paid an £8million fee to bring the 21-year-old in from White Hart Lane.
Caulker enjoyed an excellent season on-loan with Cardiff's Welsh rivals Swansea during the 2011-12 season, making 26 appearances for the Swans, and his acquisition is set to stoke the fires when the two sides meet in this season's derby fixtures.
While Rangel, who played alongside Caulker for Swansea, believes he is an excellent signing for Cardiff, he also suggested the defender should be playing for a top-six side.
He said: "Being an England international and playing for Spurs, with respect, you would expect him to go to a big club.
"He could play for Arsenal or these kind of teams. He's gone to Cardiff for some reason, I didn't expect it, but he knows he will probably be playing regularly, week-in, week-out.
"I think it will be a good move for him."
He added: "For a young defender he is a big lad, he is quick, he reads the game well and has good football in his boots. He is a complete centre-half for me.
"He is still young but he is a great signing for Cardiff, he is also a nice lad and hopefully he will do well for himself."
Rangel also admits Caulker's presence will add spice when he meets his former colleagues in November and February.
"It will add more spice having an ex-Swansea footballer in the other side," he said. "It will add more motivation seeing a player that has played here playing for our rivals.
"These games are all about emotion and excitement. Whoever plays, Cardiff against Swansea is always going to be exciting, dangerous, whatever you want to call it.
"Hopefully things will go to our side and we will win it."
Caulker, who scored a goal on his England debut in the 4-2 friendly defeat to Sweden, for his part was delighted to have secured a move which he hopes will make him a regular Premier League starter.
He told Cardiff City Player: "First and foremost I want to say how happy I am to have signed with Cardiff City Football Club. I'm delighted to be here and excited for this fresh challenge.
"I spoke to the gaffer yesterday (Tuesday), liked what he had to say and am excited about the plans he has for the football club.
"You get the sense of excitement from everybody at the club in the build-up to the season's kick-off at West Ham and I'm really looking forward to being part of it."
Caulker is Malky Mackay's fourth signing of the summer and will provide stern competition for Mark Hudson and Ben Turner at the heart of the Bluebirds defence.
Mackay has already added Danish striker Andreas Cornelius, Derby full-back John Brayford and Brentford goalkeeper Simon Moore to his squad ahead of Cardiff's maiden Barclays Premier League campaign.