Questions

India’s first indigenously designed and developed high thrust cryogenic rocket engine generating a nominal thrust of 19 tonnes was successfully endurance hot tested for a duration of 800 seconds on July 16, 2015 at ISRO Propulsion Complex, Mahendragiri.

The engine will be used for powering the Cryogenic stage (C25), the upper stage of the next generation GSLV Mark-III launch vehicle of ISRO, capable of launching four tonne class satellites.

This cryogenic engine of C25 Stage operates on Gas Generator Cycle using extremely low temperature propellants – Liquid Hydrogen (LH2) at 20 Kelvin (-253 deg C) and Liquid Oxygen (LOX) at 80K (-193 deg C).

There are 60 minutes in an hour.

In ¾ of an hour there are (60 × ¾) minutes = 45 minutes.

In ¾ of an hour there are (60 × 45) seconds = 2700 seconds.

Siren sounds for every 5 seconds.

In 2700 seconds = 2700/5 = 540 times.

The count start after the first sound, the Siren will sound 541 times in ¾ of an hour.

The Opium Wars were two wars in the mid-19th century involving Anglo-Chinese disputes over British trade in China and China’s sovereignty. The disputes included the First Opium War (1839–1842) and the Second Opium War (1856–1860).