Explanation

The power of the lens is the reciprocal of focal length.

The SI unit is dioptre.

Dioptre (D)

Power of lens = 1/ focal length in meter.

Explanation

The Temple of Heaven is located in the southeastern part of central Beijing. 

It was constructed from 1406 to 1420

During the reign of the Yongle Emperor of the Ming Dynasty.

The Anglo-French alliance occupied the temple during the Second Opium War.

Explanation

Explanation

On July 20, 1969, Neil Armstrong became the first human to step on the moon.

He and Aldrin walked around for three hours.

Born: August 5, 1930, Wapakoneta, Ohio, United States

Died: August 25, 2012, Cincinnati, Ohio, United States

Explanation

Kyoto University has several campuses

But its primary one, the Yoshida Campus

It is located in the city of Kyoto, Japan.

Established: June 18, 1897

 It is one of the former Imperial Universities and the second-oldest university in Japan

Explanation

Plaster of Paris (POP) is calcium sulfate hemihydrate (CaSO₄·½H₂O).  

It is made by heating gypsum (CaSO₄·2H₂O) to remove water partially.

Explanation

- Parrot, Eagle, Sparrow — all are birds that can fly.  

- Kiwi — a flightless bird found in New Zealand.

Explanation

The formula for sulfuric acid is H2SO4.

It indicating that one molecule contains two hydrogen atoms, one sulfur atom, and four oxygen atoms.

Explanation

 A buffer is a solution that resists change in its pH. 

A buffer solution is composed of a weak acid and its conjugate base (or a weak base and its conjugate acid).

When a small amount of a strong acid or base is added to a buffer,

The added ions react with the components of the buffer to maintain a relatively constant pH. 

Explanation

Ibn Battuta was a Maghrebi traveller, explorer, and scholar.

Over a period of 30 years from 1325 to 1354

He visited much of Africa, Asia, and the Iberian Peninsula.

His travelogue is known as "Rihla", meaning "The Journey."

Born: 24 February 1304, Tangier, Marinid sultanate

Died: 1369 (aged 64–65) Marrakesh, Marinid sultanate

Other names: The Islamic Marco Polo