20 litres of hydrogen gas at 27 C and 50 atm expands reversibly and isothermally to 200 litres. In doing so, it absorbs 400 kJ of thermal energy from its surroundings. Determine the change in internal energy of hydrogen gas for the process.

If a particle moves along a path such that r : (3 sin t) m and ? : 2t rad, where t is in seconds. what is the particle's acceleration in m/s in 4 seconds? a)- 16.43 b)- 16.29 c)- 15.21 d)- 13.79

Which of the following controllers anticipates the future from the slope of errors over time? a)-proportional b)-on/off c)-integral d)-derivative.

Awall of 0.5m thickness is to be constructed from a material which has average thermal conductivity of 1.4 w/mk. the wall is to be insulated with a material having an average thermal conductivity of 0.35 w/mk so that heat loss per square meter shall not exceed 1450 w. assume inner wall surface temperature of 1200°c and outer surface temperature of the insulation to be 15°c. calculate the thickness of insulation required.