Engineering Answers

A carnot heat pump is to be used to heat a house and maintain it at 20°c in winter. On a day when the average outdoor temperature remains at about 2°c. The house is estimated to loose heat at a rate of 82000kj/hr. If the heatpump consumes 8KW of electricity while operating l, determine how long the pump ran on that day

Consider the actual powerplants operating with solar energy. Energy is supplied to one plant from a solar pond at 80°c and to the other from concentrating collectors that raise the water temperatures to 600°c. Which of these powerplants will have a higer efficiency? Explain

A refrigerator has a COP of 1.5. That is the refrigerator removes 1.5kwh of energy from the refrigerated space for each 1kw of electricity it consumes. Is this a violation of the first law of thermodynamics? Explain

A steam powerplant operates between a boiler pressure of 30bar and a condenser pressure of 0.04bar calculate the following: 1) the heat and work transfer 2) the cycle efficiency for a carnot cycle 3) the newtwork output 4)the work ratio

A steam powerplant operates between a boiler pressure of 30bar and a condenser pressure of 0.04bar calculate the following: 1) the heat and work transfer 2) the cycle efficiency for a carnot cycle 3) the newtwork output 4)the work ratio

 How is loss of prime mover detected? What are the problems encountered in implementing this protection?

Judge the feedback polarity and configuration of multistage amplifier in the circuit.

on proteus Design a voting system with 5 voters. Inputs should be 5 inputs representing each vote. Outputs

should be a LED which turns on if majority votes are cast in favor, as well as a display of the

number of votes cast in favor and against. Any time there are three or more of the five who vote

in favor, then there is a majority, and the LED needs to turn on and appropriate number displayed.

For the votes display, use four multiplexed 7-segment displays connected as shown in the

following figure that will display both the number of votes in favor and against.

a cylindrical tank with hemispherical heads is constructed of steel sections that are welded circumferentially. the tank diameter is 1.25m, the wall thickness is 22mm, and the internal pressure is 1750 kpa. calculate the stress in the heads of the tank

The disc shown in the figure is supported by two

circular tubes of same cross section and different

lengths which both are connected to the disk at one

end and fixed to a wall at the other end. The internal

and external diameters of the tubes are8cmiD =

and10cmoD = , respectively. Calculate the angle

by which the disk rotates when subjected to a

torque of3kN.mT = . The tubes are made of steel

with Young’s modulus of200GPaE = and

Poisson’s ratio of0.3



60 cm and 40 cm