Engineering Answers

Prove that the COP of a reversible refrigerator operating between two given temperature is the maximum.

Find the approximation of the jaobi's method and gauss-seidel method for the following linear system, using 𝑥(0) = 0 :

10𝑥1 - 𝑥2 = 9,

-𝑥1+10𝑥2 - 2𝑥3 = 7,

-2𝑥2 + 10𝑥3 = 6.

A) Name some risks which Spiral Model can identify and resolve?

B) Is the number of loops present in the Spiral Model fixed? If yes, write

down the number of loops the spiral model has. If the answer is no, then

explain how and on what basis the number of loops of the spiral can be

determined with the help of a well labelled schematic diagram

Use the Euler's method and Runge-Kutta method for systems to approximate y1(0.72+0.72), y2(0.72), y2(0.72+0.72) of the following systems of first-order differential equations:

dy1/dx=y1-y2+2, y1(0)= -1

dy2/dx= -y1+y2+4x

y2(0)=0 ; 0 ≤ x ≤ 2

Three resistors of 10, 12 and "x" ohms, respectively are connected in parallel across a constant current source of 8A. Determine "x" if this resistor draws 2.5 A.

Use the classical Runge-Kutta method of order four to solve the initial value problem y' = y-t^2 +1, y(0) =05 and 0 ≤ t ≤ 3 to approximate y(0.72), y(0.72+0.72), y(0.(3×72)), y(0.(4×72)).

Use the classical Runge-Kutta method of order two, Mid-point method, Ralston's method to solve the initial value problem y' =y - t^2 +1, y(0) = 0.5 and 0 ≤ t ≤ 3 to approximate y(0.72), y(0.72+0.72), y(0.(3×72 )), y(0.(4×72)).

Use Euler's method and modified Euler's method to solve the initial value problem dy/dx = 1+x/1+y,

y(1) = 2 and 1≤ x ≤ 4 to approximate y(1.72), y(1.72+0.72), y(1.(3×72)), y(1.(4×72)),

The exact solution is given by y(x)=x+ 1/1-x . Determine the crror at cach step.

Four cubic meters of water is to be heated by means of four 1.5 kW, 230 V immersion heating elements. Assuming the efficiency of the heater as 90%, determine the time required boiling the water if the initial temperature is 20°C and if all four elements are connected in parallel.