NEW YORK: Katy Perry and Snoop Dogg are to test their general knowledge on TV after signing up to appear on a special celebrity edition of quiz show WHO WANTS TO BE A MILLIONAIRE.

Actress Vanessa Williams, The Hills star Lauren Conrad and U.S. human rights leader Revd. Al Sharpton will also feature on the popular show as it celebrates its 10th anniversary.

All the stars will have to answer one question correctly - and if they succeed, $50,000 (£33,300) will be donated to their nominated charity, according to AllHipHop.com.

The special shows will be screened in the U.S. across two weeks, beginning on Sunday (09Aug09).