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Engineering Mathematics 2015 Prepared by C.Ganesan, M.Sc., M.Phil., (Ph:9841168917) Page 1 SUBJECT NAME : Transforms and Partial Diff. Eqn. SUBJECT CODE : MA2211 MATERIAL NAME : University Questions REGULATION : R2008 WEBSITE : www.hariganesh.com UPDATED ON : May-June 2015 TEXT BOOK FOR REFFERENCE : Hariganesh Publications (Author: C. Ganesan) To buy the book visit www.hariganesh.com/textbook Name of the Student: Branch: Unit I (Fourier Series) Fourier Series in the interval (0,2ℓ) 1. Expand () 2 fx x x as Fourier series in 0, 2 and hence deduce that the sum of 2 2 2 2 1 1 1 1 ... 1 2 3 4 . (A/M 2011) Text Book Page No.: 2.6 2. Find the Fourier series of 2 ( ) fx x in 0, 2 of periodicity 2 . (M/J 2012) Text Book Page No.: 2.3 3. Find the Fourier series expansion of for 0 ( ) 2 for 2 x x fx x x . Also, deduce that 2 2 2 2 1 1 1 ... 1 3 5 8 . (N/D 2010) Text Book Page No.: 2.12

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Engineering Mathematics 2015

Prepared by C.Ganesan, M.Sc., M.Phil., (Ph:9841168917) Page 1

SUBJECT NAME : Transforms and Partial Diff. Eqn.

SUBJECT CODE : MA2211

MATERIAL NAME : University Questions

REGULATION : R2008

WEBSITE : www.hariganesh.com

UPDATED ON : May-June 2015

TEXT BOOK FOR REFFERENCE : Hariganesh Publications (Author: C. Ganesan) To buy the book visit www.hariganesh.com/textbook

Name of the Student: Branch:

Unit – I (Fourier Series)

Fourier Series in the interval (0,2ℓ)

1. Expand ( ) 2f x x x as Fourier series in 0,2 and hence deduce that the

sum of 2 2 2 2

1 1 1 1...

1 2 3 4 . (A/M 2011)

Text Book Page No.: 2.6

2. Find the Fourier series of 2

( )f x x in 0,2 of periodicity 2 .

(M/J 2012)

Text Book Page No.: 2.3

3. Find the Fourier series expansion of for 0

( )2 for 2

x xf x

x x

. Also, deduce

that 2

2 2 2

1 1 1...

1 3 5 8

. (N/D 2010)

Text Book Page No.: 2.12

Engineering Mathematics 2015

Prepared by C.Ganesan, M.Sc., M.Phil., (Ph:9841168917) Page 2

4. Find the Fourier Series Expansion of 1 for 0

( )2 for 2

xf x

x

. (N/D 2013)

Text Book Page No.: 2.10

5. Determine the Fourier series for the function ( ) sinf x x x in 0 2x .

(N/D 2014)

Text Book Page No.: 2.21

6. Find the Fourier series expansion of , 0 1

( )2 , 1 2

x xf x

x x

. Also, deduce

2

2 2 2

1 1 1...

1 3 5 8

. (N/D 2012)

Text Book Page No.: 2.38

7. Find the Fourier series for 2( ) 2f x x x in the interval 0 2x . (A/M 2010)

Text Book Page No.: 2.38

8. Obtain the Fourier series of periodicity 3 for 2( ) 2f x x x in 0 3x .

Text Book Page No.: 2.33 (N/D 2011),(N/D 2014)

Fourier Series in the interval (-ℓ,ℓ)

1. Find the Fourier series of 2x in , and hence deduce that

4

4 4 4

1 1 1...

1 2 3 90

. (M/J 2013)

Text Book Page No.: 2.42

2. Obtain the Fourier series of ( ) sinf x x x in , . (N/D 2011)

Text Book Page No.: 2.47

3. Obtain the Fourier series to represent the function ( )f x x , x and

deduce

2

21

1

82 1n n

. (M/J 2012)

Text Book Page No.: 2.45

Engineering Mathematics 2015

Prepared by C.Ganesan, M.Sc., M.Phil., (Ph:9841168917) Page 3

4. Obtain the Fourier series of the periodic function defined by

0( )

0

xf x

x x

. Deduce that

2

2 2 2

1 1 1...

1 3 5 8

. (N/D 2009)

Text Book Page No.: 2.66

5. Expand

21 , - 0

( )2

1 , 0

xx

f xx

x

as a full range Fourier series in the interval

, . Hence deduce that 2

2 2 2

1 1 1...

1 3 5 8

. (M/J 2014)

Text Book Page No.: 2.58

6. Obtain the Fourier series for the function ( )f x given by1 , 0

( )1 , 0

x xf x

x x

.

Hence deduce that2

2 2 2

1 1 1...

1 3 5 8

. (A/M 2011)

Text Book Page No.: 2.61

7. Find the Fourier series expansion of 1, 0

( )1, 0

x xf x

x x

. (N/D 2013)

Text Book Page No.: 2.61

8. Find the Fourier series of the function0, 0

( )sin , 0

xf x

x x

and hence evaluate

1 1 1...

1.3 3.5 5.7 . (N/D 2011)(AUT)

Text Book Page No.: 2.78

9. Expand 2( )f x x x as a Fourier series in L x L and using this series find the

root mean square value of ( )f x in the interval. (N/D 2009)

Text Book Page No.: 2.79

10. Find the Fourier series expansion of 2( )f x x x in , . (N/D 2012)

Text Book Page No.: 2.62

Engineering Mathematics 2015

Prepared by C.Ganesan, M.Sc., M.Phil., (Ph:9841168917) Page 4

11. Find the Fourier series expansion of 2( ) 1f x x in the interval 1,1 .

Text Book Page No.: 2.72 (N/D 2010)

Half Range Fourier Series

1. Obtain the half range cosine series for ( )f x x in 0, and hence show that

4

4 4

1 11 ...

3 5 96

. (N/D 2010),(N/D 2012),(N/D 2014)

Text Book Page No.: 2.81

2. Find the half range cosine series of the function ( ) ( )f x x x in the interval

0 x . Hence deduce that4

4 4 4

1 1 1...

1 2 3 90

. (A/M 2010)

Text Book Page No.: 2.108

3. Find the half-range Fourier cosine series of 2

( )f x x in the interval (0, ) .

Hence find the sum of the series 4 4 4

1 1 1...

1 2 3 . (M/J 2012)

Text Book Page No.: 2.95

4. Obtain the Fourier cosine series of 2

1 , 0 1x x and hence show that

2

2 2 2

1 1 1...

1 2 3 6

. (M/J 2013)

Text Book Page No.: 2.88

5. Obtain the half range cosine series for ( )f x x in 0, . (N/D 2010),(N/D 2012)

Text Book Page No.: 2.81

6. Obtain the Fourier cosine series expansion of sinx x in 0, and hence find the value

of 2 2 2 2

1 ...1.3 3.5 5.7 7.9

. (N/D 2011)

Text Book Page No.: 2.83

Engineering Mathematics 2015

Prepared by C.Ganesan, M.Sc., M.Phil., (Ph:9841168917) Page 5

7. Find the half-range sine series of 2( ) 4f x x x in the interval 0,4 . Hence deduce

the value of the series 3 3 3 3

1 1 1 1...

1 3 5 7 . (M/J 2014)

Text Book Page No.: 2.109

8. Find the half range sine series of 2( )f x x x in 0, . (N/D 2013)

Text Book Page No.: 2.86

9. Obtain the sine series for

in 02

( )

in 2

x x

f x

x x

. (A/M 2011)

Text Book Page No.: 2.109

10. Obtain the Fourier cosine series for

in 02

( )

in 2

kx x

f x

k x x

. (M/J 2013)

Text Book Page No.: 2.91

Complex Form of Fourier Series

1. Find the complex form of the Fourier series of ( )ax

f x e , x .(A/M 2010)

Text Book Page No.: 2.113

2. Show that the complex form of Fourier series for the function ( )x

f x e when

x and ( ) ( 2 )f x f x is 2

sinh 1( ) 1

1

n inx

n

inf x e

n

.

Text Book Page No.: 2.113 (N/D 2014)

3. Find the complex form of the Fourier series of ( )x

f x e in 1 1x .(N/D 2009)

Text Book Page No.: 2.117

4. Find the complex form of Fourier series of cosax in , , where " "a is not an

integer. (M/J 2013)

Engineering Mathematics 2015

Prepared by C.Ganesan, M.Sc., M.Phil., (Ph:9841168917) Page 6

Text Book Page No.: 2.115

5. Expand ( ) sinf x x as a complex form Fourier series in , . (M/J 2014)

Text Book Page No.: 2.124

Harmonic Analysis

1. Compute upto first harmonics of the Fourier series of ( )f x given by the following table

x 0 T/6 T/3 T/2 2T/3 5T/6 T

( )f x 1.98 1.30 1.05 1.30 – 0.88 – 0.25 1.98

(N/D 2009),(N/D 2011)

Text Book Page No.: 2.131

2. Find the Fourier series as far as the second harmonic to represent the function ( )f x

with the period 6, given in the following table.

(N/D 2009),(N/D 2010),(M/J 2012),(N/D 2012)

x 0 1 2 3 4 5

( )f x 9 18 24 28 26 20

Text Book Page No.: 2.129

3. Find the Fourier series up to second harmonic for ( )y f x from the following values.

x: 0 π/3 2 π/3 π 4π/3 5 π/3 2 π

y: 1.0 1.4 1.9 1.7 1.5 1.2 1.0

(A/M 2011),(N/D 2013),(M/J 2014)

Text Book Page No.: 2.127

4. Calculate the first 3 harmonics of the Fourier of ( )f x from the following data (N/D 2011)

x : 0 30 60 90 120 150 180 210 240 270 300 330

( ) :f x 1.8 1.1 0.3 0.16 0.5 1.3 2.16 1.25 1.3 1.52 1.76 2.0

Text Book Page No.: 2.133

Engineering Mathematics 2015

Prepared by C.Ganesan, M.Sc., M.Phil., (Ph:9841168917) Page 7

Unit – II (Fourier Transform)

Fourier Transform with Deduction

1. Find the Fourier transform of1 1

( )0 1

x if xf x

if x

and hence find the value of

4

4

0

sin

tdt

t

. (N/D 2009),(A/M 2010),(N/D 2011),(N/D 2012)

Text Book Page No.: 4.22

2. Find the Fourier transform of ( )f x given by 1 for

( )0 for 0

x af x

x a

and using

Parseval’s identity prove that

2

0

sin

2

tdt

t

. (A/M 2011)

Text Book Page No.: 4.22

3. Find the Fourier transform of1 for

( )0 for

x af x

x a

and hence find0

sin xdx

x

.Text

Book Page No.: 4.20 (M/J 2013)

4. Find the Fourier transform of

21 1( )

0 1

x if xf x

if x

. Hence evaluate

3

0

cos sincos

2

x x x xdx

x

. (A/M 2011)

Text Book Page No.: 4.40

5. Find the Fourier transform of

21 , 1( )

0 , 1

x xf x

x

. Hence show that

3

0

sin cos 3cos

2 16

s s s sds

s

and

2

6

0

cos sin

15

x x xdx

x

. (N/D 2013)

Text Book Page No.: 4.40

Engineering Mathematics 2015

Prepared by C.Ganesan, M.Sc., M.Phil., (Ph:9841168917) Page 8

6. Show that the Fourier transform of

2 2 , ( )

0, 0

a x x af x

x a

is

3

2 sin cos2

as as as

s

. Hence deduce that3

0

sin cos

4

t t tdt

t

. Using

Perserval’s identity show that

2

3

0

sin cos

15

t t tdt

t

. (N/D 2011),(N/D 2012)

Text Book Page No.: 4.25

Integration using Parseval’s Identity

1. Evaluate

2

2 20

dx

x a

using Parseval’s identity. (M/J 2013),(N/D 2013),(M/J 2014)

Text Book Page No.: 4.50

2. Using Parseval’s identity evaluate

2

22 2

0

xdx

x a

. (M/J 2014)

Text Book Page No.: 4.67

3. Evaluate 2 2

0 4 25

dx

x x

using transform methods. (N/D 2009)

Text Book Page No.: 4.52

4. Using Fourier cosine transform method, evaluate 2 2 2 2

0

dt

a t b t

.(A/M 2010)

Text Book Page No.: 4.67

5. Evaluate 2 2 2 2

0

dx

x a x b

using Fourier cosine transforms of ax

e and bx

e .

Text Book Page No.: 4.67 (N/D 2010),(A/M 2011)

Engineering Mathematics 2015

Prepared by C.Ganesan, M.Sc., M.Phil., (Ph:9841168917) Page 9

Fourier Transform of Exponential Function&

Self Reciprocal Problems

1. Find the Fourier sine transform of axe and hence evaluate Fourier cosine transforms of

axxe

and sinax

e ax . (N/D 2011)

Text Book Page No.: 4.58

2. Find the Fourier cosine and sine transforms of ( ) , 0ax

f x e a and hence deduce

the inversion formula. (N/D 2012)

Text Book Page No.: 4.46

3. Find the Fourier sine transformation ofax

e

x

where 0a . (N/D 2011)(AUT)

Text Book Page No.: 4.59

4. Find the function whose Fourier Sine Transform is 0as

ea

s

. (N/D 2013)

Text Book Page No.: 4.61

5. Find the Fourier cosine transform of 2

xe . (N/D 2009),(N/D 2011)(AUT)

Text Book Page No.: 4.68

6. Show that the Fourier transform of

2

2

x

e

is

2

2

s

e

. (A/M 2010),(M/J 2013)

Text Book Page No.: 4.28

7. Find the Fourier cosine transform of 2 2

, 0a x

e a . Hence show that the function

2

2

x

e

is self-reciprocal. (N/D 2012)

Text Book Page No.: 4.63

8. Show that

2

2

x

e

is a self reciprocal with respect to Fourier transform. (N/D 2011)

Text Book Page No.: 4.28

9. Find the Fourier transform of 1

( )f xx

. (M/J 2014)

Text Book Page No.: 4.31

10. Prove that1

xis self reciprocal under Fourier sine and cosine transforms.(N/D 2009)

Text Book Page No.: 4.64

11. Find Fourier sine and cosine transform of 1nx

and hence prove 1

x is self reciprocal

under Fourier sine and cosine transforms. (M/J 2012)

Text Book Page No.: 4.64

Engineering Mathematics 2015

Prepared by C.Ganesan, M.Sc., M.Phil., (Ph:9841168917) Page 10

Fourier Transform of General Function& Derivations

1. Find the Fourier sine and cosine transform of sin , 0

( )0,

x x af x

x a

. (A/M 2010)

Text Book Page No.: 4.54

2. Find the Fourier integral representation of ( )f x defined as

0 for 0

1( ) for 0

2

for 0x

x

f x x

e x

.

Text Book Page No.: 4.33 (N/D 2010),(M/J 2012)

3. Find the Fourier sine transform of

, 0 1

( ) 2 , 1 2

0, 2

x x

f x x x

x

. (N/D 2010),(A/M 2011)

Text Book Page No.: 4.55

4. Solve for ( )f x from the integral equation 0

1, 0 1

( )sin 2, 1 2

0, 2

s

f x sx dx s

s

.

Text Book Page No.: 4.39 (M/J 2014)

5. Solve for ( )f x from the integral equation 0

( )cosa

f x ax dx e

. (N/D 2014)

6. Derive the Parseval’s identity for Fourier Transforms. (N/D 2010),(M/J 2012)

Text Book Page No.: 4.13

7. State and prove convolution theorem for Fourier transforms. (N/D 2011),(M/J 2012)

Text Book Page No.: 4.12

8. Verify the convolution theorem under Fourier Transform, for2

( ) ( ) ex

f x g x .

(M/J 2013)

Engineering Mathematics 2015

Prepared by C.Ganesan, M.Sc., M.Phil., (Ph:9841168917) Page 11

Unit – III (Partial Differential Equation)

Formation of PDE and Standard Types of PDE

1. Find the partial differential equation of all planes which are at a constant distance ‘ a ’

from the origin. (A/M 2010)

Text Book Page No.: 1.25

2. Form the PDE by eliminating the arbitrary function from

2 2 2 , 0x y z ax by cz . (N/D 2010),(M/J 2012)

Text Book Page No.: 1.18

3. Form the partial differential equation by eliminating arbitrary functions f and from

( ) ( )z f x ct x ct . (A/M 2011)

Text Book Page No.: 1.20

4. Form the PDE by eliminating the arbitrary functions ‘ f ’ and ‘ g ’ from

2 2( ) ( )z x f y y g x . (N/D 2013)

Text Book Page No.: 1.23

5. Form the PDE by eliminating the arbitrary function from the relation

2 12 logz y f y

x

. (M/J 2014)

Text Book Page No.: 1.16

6. Solve 2 2z px qy p q . (N/D 2009)

Text Book Page No.: 1.44

7. Find the singular integral of 2 21z px qy p q .

Text Book Page No.: 1.40 (N/D 2011),(M/J 2013),(N/D 2013)

8. Find the singular integral of 2 2z px qy p pq q . (N/D 2012)

Text Book Page No.: 1.47

9. Solve 1p q qz (A/M 2010)

Engineering Mathematics 2015

Prepared by C.Ganesan, M.Sc., M.Phil., (Ph:9841168917) Page 12

Text Book Page No.: 1.52

10. Solve 2 29 4p z q . (N/D 2014)

Text Book Page No.: 1.53

11. Solve 2 2 2 2p q x y (A/M 2010)

Text Book Page No.: 1.61

12. Solve 2 2 2 2 2z p q x y . (N/D 2011)(AUT)

Text Book Page No.: 1.69

13. Solve 2 2 2 2 2x p y q z . (M/J 2014)

Text Book Page No.: 1.71

PDE of Lagrange’s Equation

1. Solve the partial differential equation ( ) ( )mz ny p nx z q y mx .(A/M 2011)

Text Book Page No.: 1.94

2. Solve the partial differential equation 2 2 2x y z p y z x q z x y .

Text Book Page No.: 1.101 (N/D 2010),(M/J 2012)

3. Solve the partial differential equation ( ) ( ) ( )x y z p y z x q z x y .

Text Book Page No.: 1.97 (N/D 2011)

4. Solve 2 2 2 2 2 2x y z p y z x q z x y . (N/D 2011)(AUT),(M/J 2013)

Text Book Page No.: 1.99

5. Solve 2 2 2 2 2 2x z y p y x z q z y x . (N/D 2014)

Text Book Page No.: 1.99

6. Solve ( 2 ) (2 )x z p z y q y x . (N/D 2012)

Text Book Page No.: 1.103

7. Solve ( ) ( ) ( )( )y xz p yz x q x y x y . (N/D 2009)

Engineering Mathematics 2015

Prepared by C.Ganesan, M.Sc., M.Phil., (Ph:9841168917) Page 13

Text Book Page No.: 1.105

8. Solve 2 2 0y z p xyq xz . (N/D 2013)

Text Book Page No.: 1.106

9. Solve 2 2 2x yz p y zx q z xy (A/M 2010)

Text Book Page No.: 1.110

10. Solve the Lagrange’s equation 22 2x z p xz y q x y . (M/J 2014)

Text Book Page No.: 1.108

Homogeneous Linear Partial Differential Equation

1. Solve 2 2 22 sinh( ) x yD DD D z x y e . (N/D 2009)

Text Book Page No.: 1.132

2. Solve 2 2 2 42 2 3 x yD DD D z x y e . (N/D 2013)

Text Book Page No.: 1.149

3. Solve 2 23 2 sin 5D DD D z x y . (N/D 2014)

Text Book Page No.:

4. Solve 3 2 2 34 4 cos 2D D D DD D z x y . (N/D 2010),(M/J 2012)

Text Book Page No.: 1.145

5. Solve 2 2 sin 2 3x yD D z e x y . (A/M 2011)

Text Book Page No.: 1.163

6. Solve 3 2 2 22 2 3xD D D z e x y . (N/D 2011)

Text Book Page No.: 1.175

7. Solve 2 23 4 cos 2D DD D z x y xy . (N/D 2012)

Text Book Page No.: 1.159

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Prepared by C.Ganesan, M.Sc., M.Phil., (Ph:9841168917) Page 14

8. Solve 3 2 37 6 cos 2D DD D z x y x . (N/D 2011)(AUT)

Text Book Page No.: 1.175

9. Solve 3 2 37 6 sin 2D DD D z x y . (M/J 2013)

Text Book Page No.: 1.175

10. Solve 2 26 cosD DD D z y x . (M/J 2013),(M/J 2014)

Text Book Page No.: 1.170

Non Homogeneous Linear Partial Differential Equation

1. Solve 2 2 3 3 7D D D D z xy . (N/D 2009)

Text Book Page No.: 1.190

2. Solve 2 22 2 2 sin( 2 )D DD D D D z x y . (A/M 2010)

Text Book Page No.: 1.188

3. Solve 2 22 6 3 yD DD D D D z xe . (N/D 2010),(M/J 2012)

Text Book Page No.: 1.195

4. Solve 2 23 2 2 2 sin(2 )D DD D D D z x y x y . (A/M 2011)

Text Book Page No.: 1.192

5. Solve 2 2 22 3 3 2 x yD DD D D D z e . (N/D 2011)

Text Book Page No.: 1.184

6. Solve 2 22 4x yD DD D z e . (N/D 2012)

Text Book Page No.: 1.183

Engineering Mathematics 2015

Prepared by C.Ganesan, M.Sc., M.Phil., (Ph:9841168917) Page 15

Unit – IV (Application of Partial Differential Equation)

One Dimensional Wave Equation with No Velocity

1. A string is stretched and fastened to points at a distance apart. Motion is started by

displacing the string in the form sinx

y a

, 0 x , from which it is released

at time 0t . Find the displacement at any time t . (M/J 2014)

Text Book Page No.: 3.21

2. A tightly stretched string with fixed end points 0x and x is initially in a position

given by 3

0( ,0) sin

xy x y

. It is released from rest from this position. Find the

expression for the displacement at any time t . (N/D 2012)

Text Book Page No.: 3.24

3. A uniform string is stretched and fastened to two points ‘ ’ apart. Motion is started by

displacing the string into the form of the curve ( )y kx x and then released from

this position at time 0t . Derive the expression for the displacement of any point of

the string at a distance x from one end at time t . (A/M 2011),(N/D 2013)

Text Book Page No.: 3.25

4. A string is stretched and fastened to two points 0x and x apart. Motion is started

by displacing the string into the form 2y k lx x from which it is released at time

0t . Find the displacement of any point on the string at a distance of x from one end at time t . (N/D 2011)(AUT) Text Book Page No.: 3.25

5. A tightly stretched string of length ‘ ’ has its ends fastened at 0x and x . The

mid – point of the string is then taken to height ‘b’ and released from rest in that

position. Find the lateral displacement of a point of the string at time ‘t’ from the

instant of release. (A/M 2010)

Text Book Page No.: 3.27

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Prepared by C.Ganesan, M.Sc., M.Phil., (Ph:9841168917) Page 16

6. A tightly stretched string of length 2 is fastened at both ends. The midpoint of the

string is displaced by a distance ‘b’ transversely and the string is released from rest in

this position. Find an expression for the transverse displacement of the string at any

time during the subsequent motion. (N/D 2010)

Text Book Page No.: 3.43

One Dimensional Wave Equation with Velocity

1. A tightly stretched string with fixed end points 0x and x is initially at rest in its

equilibrium position. If it is set vibrating giving each point a initial velocity 3 ( )x x ,

find the displacement. (N/D 2009)

Text Book Page No.: 3.36

2. A tightly stretched string between the fixed end points 0x and x is initially at

rest in its equilibrium position. If each of its points is given a velocity ( )kx x , find

the displacement ( , )y x t of the string. (M/J 2013)

Text Book Page No.: 3.44

3. A tightly stretched string with fixed ends points 0x and x is initially at rest in its

equilibrium position. If it is set vibrating giving each point a velocity ( )x x , show

that 3

4 41

8 1 (2 1) (2 1)( , ) sin sin

(2 1)n

n x n aty x t

a n

. (N/D 2014)

Text Book Page No.: 3.44 (Similar Problem)

4. A tightly stretched string of length ‘ ’ is initially at rest in its equilibrium position and

each of its points is given the velocity 3

0sin

xV

.Find the displacement ( , )y x t .

Text Book Page No.: 3.32 (N/D 2011)

One Dimensional Heat Equation with Both Ends Are

Change to Zero Temperature

1. Find the solution to the equation 2

2

2

u ua

t x

that satisfies the conditions

(0,t) 0, ( ,t) 0u u , for 0t and, 0 / 2

( ,0), / 2

x xu x

x x

. (N/D 2013)

Text Book Page No.: 3.53

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2. A rod, 30 cm long has its ends A and B kept at 20⁰C and 80⁰C respectively, until steady

state conditions prevail. The temperature at each end is then suddenly reduced to 0⁰C

and kept so. Find the resulting temperature function is a regular function ( , )u x t taking

0x at A. (N/D 2009)

Text Book Page No.: 3.57

One Dimensional Heat Equation with Both Ends Are

Change to Non Zero Temperature

1. A bar of 10 cm long, with insulated sides has its ends A and B maintained at temperatures

50 C and 100 C respectively, until steady-state conditions prevail. The temperature at

A is suddenly raised to 90 C and at B is lowered to 60 C . Find the temperature

distribution in the bar thereafter. (N/D 2011)(AUT)

Text Book Page No.: 3.63

2. The ends A and B of a rod 40 cm long have their temperatures kept at 0˚C and 80˚C

respectively, until steady state condition prevails. The temperature of the end B is then

suddenly reduced to 40˚C and kept so, while that of the end A is kept at 0˚C. Find the

subsequent temperature distribution ( , )u x t in the rod. (M/J 2012)

Text Book Page No.: 3.70

Two Dimensional Heat Equation

1. A rectangular plate with insulated surface is 10 cm wide and so long compared to its

width that may be considered infinite in length without introducing appreciable error.

The temperature at short edge 0y is given by20 for 0 5

20(10 ) for 5 10

x xu

x x

and

the other three edges are kept at 0°C. Find the steady state temperature at any point in

the plate. (A/M 2010),(M/J 2013)

Text Book Page No.: 3.97

2. A rectangular plate with insulated surface is 20 cm wide and so long compared to its

width that it may be considered infinite in length without introducing an appreciable

error. If the temperature of the short edge 0x is given by

10 for 0 10

10(20 ) for 10 20

y yu

y y

and the two long edges as well as the other short

edge are kept at 0°C. Find the steady state temperature distribution in the plate.

Text Book Page No.: 3.102 (A/M 2011)

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3. A square plate is bounded by the lines 0, 0, 20x y x and 20y . Its faces are

insulated. The temperature along the upper horizontal edge is given by

( ,20) (20 ),u x x x 0 20x while the other two edges are kept at 0 C . Find

the steady state temperature distribution in the plate.

Text Book Page No.: 3.83 (N/D 2010),(N/D 2011),(N/D 2014)

4. Find the steady state temperature distribution in a rectangular plate of sides a and b

insulated at the lateral surfaces and satisfying the boundary conditions:

(0, ) ( , ) 0, for 0 ;u y u a y y b

( , ) 0 and ( ,0) ( ), for 0 .u x b u x x a x x a (N/D 2012)

Text Book Page No.: 3.78

5. A long rectangular plate with insulated surface is cm wide. If the temperature along

one short edge ( 0)y is 2( ,0) ( )u x k x x degrees, for 0 x , while the other

two long edges 0x and x as well as the other short edge are kept at 0˚C , find

the steady state temperature function ( , )u x y . (M/J 2012)

Text Book Page No.: 3.106

6. An infinitely long rectangular plate with insulated surfaces is 10cm wide. The two long

edges and one short edge are kept at 0˚C, while the other short edge 0x is kept at

temperature

20 , 0 5

20 10 , 5 10

u y y

u y y

. Find the steady state temperature

distribution in the plate. (M/J 2014)

Text Book Page No.: 3.110

Unit – V (Z - Transforms)

Simple problems on Z - transforms

1. Find ( 1)( 2)Z n n n . (M/J 2012)

Text Book Page No.: 5.18

2. Find the Z – transform of 1

( 1)( 2)n n . (N/D 2013)

Text Book Page No.: 5.38

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3. Find the Z – transform of cosn and sinn . Hence deduce the Z – transforms of

cos 1n and sinn

a n . (N/D 2010)

Text Book Page No.: 5.21

4. Find cosZ n and hence deduce cos2

nZ

. (M/J 2013)

Text Book Page No.: 5.21

5. Find the Z – transform of 2

sin4

n

and cos2 4

n n

. (N/D 2012)

Text Book Page No.: 5.24

6. Find the Z – transforms of cosn

a n and sinat

e bt . (A/M 2011)

Text Book Page No.: 5.21; 5.31

7. Find the Z – transforms of cosn

r n and cosat

e bt

. (M/J 2014)

Text Book Page No.: 5.38; 5.31

8. Find sinn

Z na n . (A/M 2010)

9. If ( ) ( )Z f n F z , find ( )Z f n k and ( )Z f n k . (N/D 2011)

Text Book Page No.: 5.8

10. State and prove the second shifting property of Z-transform. (M/J 2013)

Text Book Page No.: 5.7

11. State and prove the final value theorem on Z-transform. (N/D 2014)

Inverse Z - transform by Partial Fraction

1. Find the inverse Z – transform of 2

10

3 2

z

z z . (N/D 2009)

Text Book Page No.: 5.41

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2. Find the inverse Z – transform of

3

3

20

2 4

z z

z z

. (N/D 2009)

Text Book Page No.: 5.48

3. Find 2

1

2

2

( 1)( 1)

z z zZ

z z

and 1

( 1)( 2)

zZ

z z

. (A/M 2010)

Text Book Page No.: 5.45; 5.70

4. Evaluate 31

5Z z

for 5z . (N/D 2011)

Text Book Page No.: 5.52

Inverse Z - transform by Residue Theorem

1. Find the inverse Z – transform of 3

( 1)

( 1)

z z

z

by residue method. (N/D 2010)

Text Book Page No.: 5.61

Inverse Z - transform by Convolution Theorem

1. Using convolution theorem, find the 1Z

of

2

4 3

z

z z . (N/D 2009)

Text Book Page No.: 5.77

2. Using convolution theorem, find inverse Z – transform of 2

( 1)( 3)

z

z z .

Text Book Page No.: 5.76 (A/M 2011),(N/D 2013)

3. Using convolution theorem, find the inverse Z – transform of 2

2( )

z

z a. (N/D 2012)

Text Book Page No.: 5.74

4. State and prove convolution theorem on Z-transformation. Find 2

1

( )( )

zZ

z a z b

.

Text Book Page No.: 5.75 (N/D 2011)(AUT)

5. Using convolution theorem, find 2

1

( )( )

zZ

z a z b

. (M/J 2013),(M/J 2014)

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Text Book Page No.: 5.75

6. Using Convolution theorem, find the inverse Z – transform of 2

8

(2 1)(4 1)

z

z z .

Text Book Page No.: 5.78 (M/J 2012)

7. Using Convolution theorem, find2

1 8

(2 1)(4 1)

zZ

z z

. (N/D 2014)

Text Book Page No.: 5.81

8. Using convolution theorem, find the inverse Z – transform of

3

4

z

z

. (A/M 2010)

Text Book Page No.: 5.80

Formation & Solution of Difference Equation

1. Form the difference equation from the relation .3n

ny a b . (N/D 2010)

Text Book Page No.: 5.83

2. Derive the difference equation from ( 3)n

ny A Bn . (A/M 2011)

Text Book Page No.: 5.84

3. Form the difference equation form ( ) 2n

y n A Bn . (N/D 2013)

Text Book Page No.: 5.111

4. Form the difference equation of second order by eliminating the arbitrary constants A

and B from ( 2)n

ny A Bn . (N/D 2011)

Text Book Page No.: 5.85

5. Using Z-transform solve2 1

3 10 0n n n

y y y ,

01y and

10y .

Text Book Page No.: 5.87 (M/J 2013),(M/J 2014)

6. Solve the equation2 1

6 9 2n

n n nu u u

given

0 10u u . (N/D 2009),(N/D 2012)

Text Book Page No.: 5.91

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7. Solve by Z – transform 2 1

2 2n

n n nu u u

with

02u and

11u .(A/M 2010)

Text Book Page No.: 5.112

8. Solve2 1

4 3 2n

n n ny y y

with

00y and

11y , using Z – transform.(N/D 2010)

Text Book Page No.: 5.111

9. Solve: 2 1

4 3 3n

n n nu u u

given that

0 10, 1u u . (N/D 2011)

Text Book Page No.: 5.112

10. Solve 2 1

3 2 4n

n n nu u u

, given that

0 10, 1u u . (M/J 2014)

Text Book Page No.: 5.93

11. Solve ( 2) ( ) 1, (0) (1) 0y k y k y y ,using Z-transform. (M/J 2012)

Text Book Page No.: 5.96

12. Using Z-transform solve the difference equation2 1

2n n n

y y y n given

0 10y y . (N/D 2013)

Text Book Page No.: 5.98

13. Solve2

2 .n

n ny y n

, using Z-transform. (M/J 2012)

Text Book Page No.: 5.101

14. Using Z-transform, solve2 1

4 5 24 8n n n

y y y n given that

03y and

15y

.Text Book Page No.: 5.112 (N/D 2011)(AUT)

15. Solve the difference equation ( 3) 3 ( 1) 2 ( ) 0y n y n y n , given that (0) 4y ,

(1) 0y and (2) 8y . (A/M 2011),(N/D 2012),(N/D 2014)

Text Book Page No.: 5.89

Text Book for Reference:

“TRANSFORMS AND PARTIAL DIFFERENTIAL EQUATIONS”

Publication: Hariganesh Publications Author: C. Ganesan

To buy the book visit www.hariganesh.com/textbook

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