Steam undergoes an isentropic compression in an insulated piston–cylinder assembly from an initial state where T₁ = 120°C, p₁ = 1 bar to a final state where the pressure p₂ = 30 bar.


Determine the final temperature, in °C, and the work, in kJ per kg of steam.

A set of ceramic parts are tested and the stress required for failure is measured; the results are as follows: 152 MPa, 260 MPa, 500 MPa, 1150 MPa, 700 MPa, 640 MPa, 370 MPa, 1020 MPa, and 1590 MPa. Calculate the Weibull modulus for the material. Discuss whether the material would be a good choice if we wished to design a reasonably reliable part.

According to Breguet range equations, what are techniques to increase range and endurance?

Steam at 4800 lbf/ in.², 1000°F enters the first stage of a supercritical reheat cycle including two turbine stages. The steam exiting the first-stage turbine at 600 lbf /in.² is reheated at constant pressure to 1000°F. Each turbine stage and the pump has an isentropic efficiency of 91%. The condenser pressure is 1 lbf/ in.² If the net power output of the cycle is 100 MW, determine

(a) the rate of heat transfer to the working fluid passing through the steam generator, in MW.
(b) the rate of heat transfer from the working fluid passing through the condenser, in MW.
(c) the cycle thermal efficiency.

QUESTION 1

Which components form the interface between the electronic signal processor (data processing) and the actual process (mechanical motion)?

QUESTION 2

Design selection of appropriate actuator is determined by operating conditions which can be:

QUESTION 4

Which of the following motors are inexpensive and used in the door locks, window lifts, antenna retractor, anti-lock braking systems and cordless hand drill?

QUESTION 4

Which of the following motors are inexpensive and used in the door locks, window lifts, antenna retractor, anti-lock braking systems and cordless hand drill?

QUESTION 5

Which of the following motors are used when you need a precise speed control such as the one in the laser printers and photocopiers?

QUESTION 6

Torque is proportional to the:

QUESTION 7

Stepper motor with 100 steps has which resolution?

QUESTION 8

Pulse with modulation is achieved with the:

QUESTION 9

Stepper motors can be used in the following industrial applications:

QUESTION 10

If you have 10 V pulse with modulation signal provided to step motor, what is the duty cycle you need to have to achieve power of 2 V?

5. Commonly used elements for wire strain gauges are __________

a) nickel and copper

b) nickel and gold

c) gold and brass

d) silver and aluminum

6. Proper functioning of a strain gauge depends on __________

a) strain

b) stress

c) bonding

d) length of wire

7. Semiconductor gauges are more sensitive than metal gauges---------

(a)True

(b) False

8. A capacitive transducer works on the principle of ________

a) inductance

b) capacitance

c) resistance

d) reluctance

9. Capacitance can be varied in ________

a) 10 ways

b) 6 ways

c) 2 ways

d) 4 ways

10. Capacitive transducer displays ________

a) linear behaviour

b) non-linear behaviour

c) exponential behaviour

d) tangential behaviour

11. Frequency response of capacitive transducers is ________

a) high

b) medium

c) low

d) zero

12. What does a piezoelectric material generate in response to an applied forece?

a) Electricity

b) Sound

c) Movement

d) Heat

13. Piezoelectric materials are -----

a) Metals

b) polymers

c) ceramics

d) Composites

14. The vibration frequency of quartz

a) 1kHz

b) 10 kHz

c) 20 KHz

d) 30 KHz

15.The purpose of diaphragm of piezoelectric pressure sensors is --------------

a) To convert pressure to electricity

b) To protect the crystal

c) To protect vacuum space

d) To protect piezoelectric layers

16. An applied voltage will cause a piezoelectric crystals to .......

a) Change direction

b) Change chemical structure

c) Change shape

d) Change color

17. Which type of accelerometer is most widely used for measuring vibration and shock?

a) Capacitive

b) MEMS

c) Piezoelectric

d) Piezoresistive

18. MEMS-based accelerometers are typically:

a) Capacitive

b) Inductive

c) Microphone

d) Piezoelectric

e) Piezoresistive

f) Piezoinductive

A cylindrical tube of mean radius 1” and wall thickness 0.1” is subjected to an internal pressure p = 300 psi and a torque T = 2000 lb-in. The ends of the tube are closed. Find the safety factor against yielding if the material yields in uniaxial tension at SY = 8 ksi and Von Mises theory is used.

An isentropic pump compresses water between the pressures listed in Problem 1 (30 & 8000 kPa) at the same mass flow rate (3 kg/s). Assuming saturated liquid conditions at the inlet of the pump, determine:

a) The power required to operate the pump

b) The ratio of the turbine power output from problem 1 to the required power input of the pump

Q1. You want to keep the indoor temperature of an office at 25oC. The outdoor temperature is 5oC. The heat transfer through the building’s exterior is 3 x 106 kJ. To achieve the desired indoor temperature, you are exploring three heat pumps operating between the office interior and: (i) the ground at 12oC; (ii) a pond at 10oC; and (iii) the air outside at 5oC.

For each case, what is the minimum theoretical net work input (in kJ) any heat pump would require?

What are some topics to discuss relating to the public, safety, and welfare in regards to the challenger space shuttle explosion?

Consider a steam power plant operating on a simple ideal Rankine cycle in which the steam enters the turbine at 3 MPa and 350C and is condensed in the condenser at 75 kPa. Determine the thermal efficiency of this cycle and sketch an appropriately labeled T-s diagram. Also compare this thermal efficiency to that a Carnot heat engine operating between these same two limits.

The change in enthalpy across the pump = work done by the pump: h2-h1= v1(P2– P1)

5. Estimate the life (in hours) of an 02-series single-row deep-groove ball bearing with a 50-mm bore working under the following condition: axial force = 4 kN, radial force = 6 kN, outer ring rotating at 360 rpm, temperature = 50 °C, light impact, reliability = 97%. (6 points)

Air enters a turbine operating at steady state at 6 bar, 1200 K and expands to 0.8 bar. The turbine is well insulated, and kinetic and potential energy effects can be neglected.

Assuming ideal gas behavior for the air, what is the maximum theoretical work that could be developed by the turbine in kJ per kg of air flow?