## Derive an equation relating the temperatures of oil and water at any section of the heater.

A.    A tubular heater of the counterflow type is used to heat 1.26 kg/s of fuel oil (cp = 3.14 kJ/kg K) from 10∞C to 26.7∞C. Heat is supplied by means of 1.51 kg/s of water which enters the heater at 82∞C.

(a) Derive an equation relating the temperatures of oil and water at any section of the heater.

(b) Determine the necessary surface area if the overall heat transfer coefficient is 1.135 kW/m2 K.

B.    A one shell pass, two tube pass heat exchanger has a total surface area of 5 m2, and its overall heat transfer coefficient based on that area is found to be 1400 W/ m2 K. If 4500 kg/h of water enters the shell side at 315∞C while 9000 kg/h of water enters the tube side at 40∞C, find the outlet temperatures using (a) the F-LMTD method and (b) the e-NTU method. Take cp for both fluid streams as 4.187 kJ/kg K.

### 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….