Question 1
[25]
LJ
Newton’s law of cooling states that the rate of cooling of a body is directly proportional
to the temperature difference between the body and the surroundings
1.1.1 Formulate the differential equation and determine the temperature of the body
(10)
at any time, t.
1.1.2 A body at a temperature of 80°C cools to 60°C in 30min in a room
(5)
temperature environment of 300C. Find the temperature of the body after
16 min.
12 Solve the equation
xd +y(x+1) = 9x;y(1) = 15
(5)
1.3
Solve the initial value problem ty’ + 3y = 0, y (1) = 2, assuming t > 0
(5)
Question 2
[25]
2.1
A series circuit consists of a resistor with R = 40 , an inductor with L= 1H, a capacitor with
C=16x 10*F are connected with E(t) =100 cos10t. The circuit initial charge and current are
both zero.
2.1.1 Find the charge and current at time (t) in the circuit using the differential
(15)
equation of the above circuit
2.1.2 | Write down the steady state solution of the equation.
(5)
2.2 Solvey”+4y =e
Question 3
3.1
1 -l
IfA=
3
1
12
0 1]
andB=|2
3
1 |. find AB
1
3.2
Solve the system of equations using Gauss-Jordan elimination method
2x-3y =-21
3x- 2y=1
8x-5y = -49
3.3
Find the eigenvalues and eigenvectors of the 3 x 3 matrix
2 -1
Q
{=} -1l
2 —]1
(10)
[25]
(5)
(10)
(10)