Explanation: Jantar Mantar is a significant astronomical observatory located in Jaipur, Rajasthan, India. It was constructed by Maharaja Sawai Jai Singh II, a scholar and astronomer, in the early 18th century. The term "Jantar Mantar" is derived from Sanskrit, where "Jantar" means instrument and "Mantar" means formula or calculation. This observatory is a testament to the advanced understanding of astronomy and mathematics in ancient India.
The Jaipur Jantar Mantar is one of five such observatories built by Sawai Jai Singh II, with others located in Delhi, Ujjain, Mathura, and Varanasi. Each observatory was designed to serve as a tool for astronomical observations and calculations. The Jaipur observatory, in particular, is renowned for its architectural grandeur and scientific precision.
The observatory consists of 19 major geometric devices, each designed to perform specific astronomical functions. These instruments include the Samrat Yantra, which is the largest sundial in the world and can measure time to an accuracy of 2 seconds. Other notable instruments include the Jai Prakash, which is used to determine the position of celestial bodies, and the Ram Yantra, which is used to measure the altitude and azimuth of celestial bodies.
The instruments at Jantar Mantar are not only functional but also architecturally impressive. They are made of stone and marble, and their design reflects a deep understanding of geometry and trigonometry. The observatory was used to predict solar and lunar eclipses, track the movement of stars, and determine the positions of planets.
The historical significance of Jantar Mantar lies in its role as a center for astronomical research and education. It was a place where scholars and astronomers could gather to study the heavens and make precise calculations. Today, Jantar Mantar is recognized as a UNESCO World Heritage Site and continues to be a source of fascination for visitors and researchers alike.
In summary, Jantar Mantar in Jaipur is a calculating instrument with 19 instruments, reflecting the advanced astronomical knowledge and architectural skills of ancient India. The correct answer is (B) Calculating instrument, 19.