According to the Badminton Information website (refer to the link, below), modern badminton racquets "shall not exceed 680mm [approximately 26.8 inches] in overall length and 230 mm [approximately 9 inches] in overall width."
According to the USTA Rules (refer to the link, below), modern tennis racquets "shall not exceed 29.0 inches overall length, including the handle. The frame of the racket shall not exceed 12.5 inches in overall width."
Given the above, a tennis racquet can be larger than a badminton racquet. However, for the record, tennis racquets can be (and have been) smaller than a badminton racquet, but that would be impractical for most modern players, as the shorter tennis racquet would not be as powerful as a larger one.
For badminton, you need at least two badminton racquets, shuttlecocks (or birdies), a net or badminton string, and proper clothing and tennis shoes.
Babolat is a French sports equipment manufacturer that produces strings and tennis racquets for tennis, badminton and squash. Famous sportsmen like Roddick, Nadal or Clijsters use their racquets.
In the old days tennis racquets were made of wood or metal. Technology has enhanced tennis racquets, and has made the game easier, and gives the athlete a larger chance to do more with the ball.
Tennis, Squash or racquet ball.
Tennis racquets are sold at almost all major sporting goods stores, including Dicks and Sports Authority. Major retailers like Walmart also carry tennis racquets.
They're store-bought racquets with the excepts of Rokkaku in which the coach personally designs each player's racquet. For real-life Prince of Tennis racquets, they're occasionally stocked as official merchandise that can be found on the official Prince of Tennis website or in anime conventions.
Adult racquets are usually longer and heavier than junior racquets
Toward the end of their popularity in the late 1970s, top wooden racquets like the Kramer Autograph sold for around US $50. The Kramer Pro Staff commanded about $5 more; the Davis TAD Imperial, about the same.
Neither. Tennis uses a tennis ball and Badminton uses a birdy.
The size of tennis racquet you choose is really a personal preference. Basically, tennis racquets come in a mid-size and oversize. The mid-size racquet has a smaller tennis face and less surface area of tennis strings. Mid-size racquets are more compact and usually lighter. They are easier to swing and move around quickly. Serve and volley type players often prefer the smaller mid-size racquet. An oversize racquet has a large surface area of tennis strings. This can make the racquet feel heavier and it is more difficult to swing the racquet around quickly. However, the "sweet" spot on the racquet is larger. The sweet spot is where you want the ball to hit your strings more maximum effectiveness. Players that hug the baseline tend to enjoy using an oversize racquet. You can always "demo" different racquets at your tennis club to see which size is best for you. Your tennis pro can also give you great reccomendations.
http://tennis.about.com/od/racquetsballsstringing/a/evolmodracquet.htm
Badminton is... not tennis