Tpde r13 Aprilmay 15
Tpde r13 Aprilmay 15
Tpde r13 Aprilmay 15
1. Form the partial differential equation by eliminating the arbitrary constants a and b form
log(az -1) x ay b .
Text Book Page No.: 1.79
3. The instantaneous current ' i ' at time t of an alternating current wave is given by
i I1 sin t 1 I 3 sin 3 t 3 I 5 sin 5 t 5 ... . Find the effective value of
the current ' i ' .
Text Book Page No.: ----
z
9. If Z x(n) X ( z ) , then show that Z a n x( n) X .
a
Text Book Page No.: 5.4
PART B – (5 x 16 = 80 marks)
11. a) (i) Solve: x 2 yz p y 2 xz q z 2 xy .
(ii) Solve: D2 3 DD 2 D 2 z (2 4 x )e x 2 y .
(Or)
(Or)
b) (i) Find the Fourier series of f ( x ) sin x in x of periodicity 2 .
(ii) Compute upto the first three harmonic of the Fourier series of f ( x ) given by the
following table:
u 2u
13. a) Solve a 2 2 subject to the conditions: u(0,t) 0 u( ,t), t 0 ;
t x
x, 0 x /2
u( x , 0) .
x, / 2 x
(Or)
b) A string is stretched and fastened to two points that are distance apart. Motion is started by
displacing the string into the form y k lx x 2
from which it is released at time t 0 . Find the
displacement at any point of the string at a distance x from one end at any time t .
sin 2 t
Using Parseval’s identity, prove that 2 dt .
0
t 2
transform of e a , a 0.
2 2
x
and Z 1 az .
2
1 1
15. a) (i) Find Z r n cos n
(Or)
b) (i) Using Z - transform, solve the difference equation x(n 2) 3 x(n 1) 2 x(n) 0
given that x(0) 0 , x(1) 1 .