Friction is the force resisting the relative motion of solid surfaces, fluid layers, and material elements sliding against each other. Friction is used to heat and ignite matchsticks ie. friction between the head of a matchstick and the rubbing surface of the match box.

According to Article 71 of the Indian Constitution, all doubts and disputes arising out of or in connection with the election of a President or Vice-President shall be inquired into and decided by the Supreme Court.

The 2019 Asian Wrestling Championships was held in Xian, China. The event took place from April 23 to April 28, 2019. Iran topped the medal tally with total 17 medals including 11 gold and 6 bronze medals and India was on the 8th spot with 16 medals.

Dr. Negasso Gidada, the former President of Ethiopia, has passed away in Frankfurt, Germany on April 27, 2019. He was president between 1995 and 2001 and was the first head of state after Ethiopia adopted a new constitution transforming the country into a federal state, with increased autonomy given to the different regions.

India’s Bajrang Punia is first Indian wrestler to be invited by American wrestling body for a special fight at iconic Madison Square Garden in New York, US. He will be among other top wrestlers selected by American governing body for 6 May 2019 tournament.

Gaj Yatra is an 18-month-long national campaign aimed to protect elephants, India’s national heritage animal in 12 elephant range states. It was organized in the Garo Hills of Meghalaya.

Scientists from the University of Minnesota, US have discovered that chemical element ruthenium (Ru) is fourth element to have unique magnetic properties (ferromagnetism) at room temperature. Thus, it is the fourth element after Iron, Cobalt and Nickel to show ferromagnetic behaviour at room temperature.

The United Nations Environment Programme (UNEP) recognized Cochin International Airport Ltd (CIAL) in Kerala as the world’s first fully solar energy-powered airport. CIAL is India’s first airport to be constructed in public-private-partnership (PPP) model in 1999.

Olga Tokarczuk was awarded the Man Booker International Prize 2018. She won prize with English translation of her novel Flights, which charts multiple journeys in time, space and human anatomy. It was first published in Polish language in 2007 and was translated into English in 2017 by Jennifer Croft.

Surya Kiran series of bilateral military exercises are conducted bi-annually ie. Every six months alternatively held in India and Nepal. It aims at promoting military relations and increasing interoperability armies of both countries.