Questions

The function of PAD (Packet Assembler Disassembler) is described in a document known as X.3. The standard protocol has been defined between the terminal and the PAD, called X.28; another standard protocol exists between hte PAD and the network, called X.29. Together, these three recommendations are often called "triple X"

Relegate means Assigning an inferior rank or position to. That means, downgrading or pulling down, lower a person.

All other options have words with opposite in meaning.

Hence, Relegate is an English word which is similar in meaning to Downgrade.

26.

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).