## What are the mole and mass fractions of air in the pipe when the ammonia fl ow rate is 5 kg/h.

A.     Helium gas is stored at 20°C in a spherical container of fused silica, which has an inner diameter of 0.20 m and a wall thickness of 2 mm. If the container is charged to an initial pressure of 4 bar, what is the rate at which this pressure de creases with time?

B.     To maintain a pressure close to atmosphere, an industrial pipeline containing ammonia gas is vented to ambient air. Venting is achieved by tapping the pipe and inserting a 3 mm diameter tube, which extends for 20 m into the atmosphere. With the entire system operating at 25°C, determine the mass rate at which ammonia is lost to the atmosphere and the mass rate of contamination of the pipe with air. What are the mole and mass fractions of air in the pipe when the ammonia fl ow rate is 5 kg/h. Given: For ammonia-air system at 298 K, D = 0.28 ¥ 10–4 m2/s.

### Calculate the maximum achievable bridge out-of-balance voltage for an applied torque T of 103 N m given the following

Four strain gauges, with specification given below, are available to measure the torque on a cylindrical shaft 4 cm in diameter connecting a motor and load. (a) Draw clearly labelled….

### Find the gain and phase characteristics of the maintaining amplifier.

A solid-state capacitive humidity sensor has a capacitance given by: C = 1.7 RH + 365pF where RH is the percentage relative humidity. The sensor has an associated parallel resistance….

### calculate the mean velocity of the gas at maximum flow rate

A pitot tube is used to measure the mean velocity of high pressure gas in a 0.15 m diameter pipe. At maximum flow rate the mean pitot differential pressure is….