These are the world's most powerful people

When it comes to power, politics trumps business, according to a new Forbes ranking that found heads of state occupying six of the top 10 spots among the world's most powerful people, led by US President Barack Obama. Prime Minister Manmohan Singh was ranked 19, while Congress president Sonia Gandhi was 12th.

Here are the top 20 who made the list:

Rank 1 | Barack Obama

Barack Obama is the 44th president of the United States, and the first African-American to hold the post. He was elected to a second term in the 2012 election held on November 6.

Rank 2 | Angela Merkel

Angela Merkel is the Chancellor of Germany, the first woman to hold the post. She is effectively the backbone of the 27-member European Union.

Rank 3 | Vladimir Putin

Vladimir Putin is the President of Russia. He previously served as president from 2000 to 2008, and as Prime Minister from 1999 to 2000, and again from 2008 to 2012. He is serving his current term since May 2012.

Rank 4 | Bill Gates

Gates is the co-founder and chairman of Microsoft and is consistently ranked among the world's richest people. He is also the co-chairman of the Bill and Melinda Gates Foundation.

Rank 5 | Pope Benedict XVI

The Pope, born Joseph Aloisius Ratzinger, is the 265th person to hold the post, and became the supreme leader of the Catholic faith in April 2005 after the death of Pope John Paul II.

Rank 6 | Ben Bernanke

Bernanke is the chairman of the US Federal reserve, the central bank of the United States. In the third round of quantitative easing announced in September, the regulator launched a $40 billion a month open-ended, bond purchasing programme of agency mortgage-backed securities.

Rank 7 | Abdullah bin Abdul Aziz al Saud

The king of Saudi Arabia controls 20 per cent of the world's known oil reserves and guards Islam's holiest cities. He ascended to the throne in August 2005, after the death of his half-brother King Fahd.

Rank 8 | Mario Draghi

Draghi is the president of the European Central Bank. As chief banker of the world's largest currency area — the euro zone's collective GDP is now more than $17 trillion — Draghi faces the Herculean task of trying to maintain financial unity across 17 countries, says Forbes.

Rank 9 | Xi Jinping

Xi is the general secretary of the Communist Party of China. He was recently promoted to the Communist Party's top position, and also took over as chairman of the Party's Central Military Commission.

Rank 10 | David Cameron

Cameron is the Prime Minister of the United Kingdom. Two years into office, he has gone from being called the second coming of Margaret Thatcher to standing in the shadow of Europe's new Iron Lady, Angela Merkel, writes Forbes.

Rank 11 | Carlos Slim Helu and family

Slim is ranked the richest man in the world, and has held the post since 2010. He has made his fortune in the fields of telecom, retailing and finance. Presently he is the chairman of Telmex and chief executive of America Movil.

Rank 12 | Sonia Gandhi

Gandhi is the president of the Indian National Congress, the leading party in the United Progressive Alliance coalition.

Rank 13 | Li Keqiang

Li is the vice-premier of China. He is expected to become Premier in early 2013 when the full National People's Congress convenes, and is expected to hold the position for two five-year terms.

Rank 14 | Francois Hollande

Hollande is the 24th and the current President of France. He defeated Nicolas Sarkozy in May.

Rank 15 | Warren Buffett

Buffett, a billionaire investor, is the chief executive of Berkshire Hathaway and is consistently ranked among the world's wealthiest people. In 2012, he was named by 'Time' as one of the most influential people in the world.

Rank 16 | Michael Bloomberg

Bloomberg is the mayor of New York City and also the founder and majority-stake owner of Bloomberg LP, a financial data services firm.

Rank 17 | Michael Duke

Duke is the chief executive of Wal-Mart Stores, the world's largest retailer and biggest private employer. He joined the company in 1995 and became CEO in February 2009.

Rank 18 | Dilma Rousseff

Rousseff is the President of Brazil, the first woman as well as the first economist to hold the post.

Rank 19 | Manmohan Singh

Singh is the only Prime Minister since Jawaharlal Nehru to return to power after completing a full five-year term. His quiet intellectualism is increasingly seen as timid and soft, says Forbes.

Rank 20 | Sergey Brin and Larry Page

They are the founders of search engine giant Google, a company they set up while attending Stanford University. Page (left) is now the chief executive of the company, while Brin handles special projects.