Tancet 2012 Basic Engg

2012 PART 02 – BASIC ENGINEERING AND SCIENCES (Common to all candidates) (Answer ALL questions) 31.. 31

A weigh weightt of 3000 3000 N is supp support orted ed by two two chain chains s as shown in Fig. below. Then Tl and T2 are respectively given by

35.. 35

36.

A ball ball of weig weight ht 120 120 N rests rests in in a right right angled angled groove as shown in Fig. The sides of the groove are inclined at an angle of 30° and 60" to the horizontal If all the surfaces are smooth, the reaction R A is given by

I f c yc yc li li c

 T  1) r e v e r s i b l e 3) i m p o s s i b l e

A cent centri rifu fuga gall fan fan fo form rms s 1) c l o s e d s y s t e m 2) o p e n s y s t e m 3) i s o l a t e d s y s t e m 4) n o n e o f t h e a b o v e

39.. 39

In a revers reversible ible adia adiabati batic c process process,, the ratio ratio of   T 1 / T 2  is equal to

34.. 34

E/TANCET-MBA-MCA-2005-08/mech-a E/TANCET-MBAMCA-2005-08/mech-auto-aero-engg-2008/ts1 uto-aero-engg-2008/ts1

 p2    p1 

2) 

γ− 1 γ 

  v1     v 2 

3) 

γ− 1 γ 

  v 2     v1 

4) 

γ− 1 γ 

Internall energy Interna energy of an idea ideall gas is a funct function ion of  of  1) tempe temperature rature and volum volume e 2) pre pressu ssure re and volu volume me 3) press pressure ure and and tempe temperatur rature e 4) tem temper peratu ature re alone alone

41.. 41

Knocking Knocki ng of of petro petroll is att attribu ributed ted to 1) pre pre-i -igni gniti tion on 2) self-i self-ignitio gnition n in the absence absence of pre-ignitio pre-ignition n 3) prepre-igni ignitio tion n and self-igniti self-ignition on 4) self-ign self-ignition ition in in the presence presence of air

42. Which Which one one of the the follow following ing stat stateme ements nts is is correc correctt with respect to the order of a reaction? 1) order is equal equal to total total stoichiome stoichiometric tric number number of products products 2) orde orderr is equal to total total stoichiom stoichiometric etric number number of reactants reactants 3) order is equal to total stoichiometric stoichiometric number of products multiplied by that of reactants 4) order is equal to the difference difference between between the total stoichiometric number of products and that of the reactants

A unifo uniform rm ladd ladder er of leng length th 10m and weig weighing hing 20N is placed against a smooth vertical wall with its lower end 8m from the wall. In this position the ladder is just to slip. The coefficient of friction between the ladder and the floor is 1) 0 . 2 5 2) 0 . 3 3 5 3) 0 . 3 4) 0 . 6 7

SAKTHI

γ− 1 γ 

40.. 40

2) 1 2 0 N 4) 1 0 3 . 9 2 N

A cir circul cular ar dis disc c of dia diamet meter er 100 cm and thickness 3cm has a mass of 200kg . If it is rotating with an angular velocity of 100 r/s the kinetic energy possessed by the disc is 1) 1 25 25 × 1 04 N c m 2) 1 2 5 × l 0 4 k N cm 3) 2 50 50 × l 04 N c m 4) 2 5 0 × l 0 7  N cm

2) irreversible 4) n o n e o f t h e a b o v e

38.

 p1    p2 

33.. 33

>0, the cycle is

The amoun amountt of heat adde added d to a gas unde underr isothermal condition is used for 1) t e m p e r a t u r e r i s e 2) d o i n g e x t e r n a l w o r k 3) increasing internal energy 4) all of the the abo above ve

1) 

1) 6 0 N 3) 3 0 N

dQ

37.. 37 1) 3 00 00 0 N a an n d 2 59 59 8 N 2) 2 59 59 8 N a an n d 3 00 00 0 N 3) 1 5 50 0 0 N an an d 2 59 59 8 N 4) 2 5 59 9 8 N an an d 1 50 50 0 N 32.. 32

A flywhee flywheell is rotat rotating ing at at 200 rpm and and after after 10 seconds it is rotating at 160 rpm. If the retardation is uniform, the retardation of the  flyw  fl ywhe heel el bef b efor ore e comin co min g to rest r est i s 2 2 1) 0. 0.42 42 r/ r/ss 2) –0.42 –0.42 r/s 3) 0. 0.84 84 r/ r/ss2 4) –0.84 r/s2

1

ME - BASIC ENGINEERING AND SCIENCES - 2012

43.

44.

Retention volume in a chromatographic experiment 1) increases with decreasing length of the column and lower flow rate of eluent 2) decreases with decreasing length of the column at constant flow rate of eluent 3) decreases with increasing column length at constant flow rate of eluent 4) increases with increasing length and higher flow rate eluent

52. A search begins the search with the element that is located in the middle of the array 1) s er ial 2) r an dom 3) p ar al lel 4) b in ary 53.

Which one of the following chromatographic techniques is useful in the identification of  54. organic molecules having molecular weights more than 20,000? 1) reverse phase chromatography 2) normal phase chromatography 3) high pressure liquid chromatography 55. 4) gel permeation chromatography

Newton’s law of viscosity relates 1) pressure, velocity and temperature 2) shear stress and rate of angular deformation in a fluid 3) shear stress, temperature, viscosity and velocity 4) pressure, viscosity and rate of angular deformation. A water sample has a hardness of 250 mg/L of CaCO 3, the above water sample is generally classified as 1) S oft 2) Moderately hard 3) Hard 4) Very Hard A dimensionless group formed with the  vari ab le s densit y ρ , angular velocity ω ,  viscosity µ  and the diameter D is, 1) ρωµ  / D2 2) ρω D 2 / µ 3) ρωµD2 4) ρωµD

45. Electrolysis was carried out in two separate cells connected in series one cell containing auric and another cupric solution. The weight of gold deposited in 3 hours was 5.91 g. The weight of  56. The friction factor f in a laminar flow was  found to be 0.05. Th e Reynolds number of  copper deposited in the second cell is 1) 2.86 g 2) 4.29 g 3) 1.43 g 4) 5.72 g the flow would be 1) 1980 2) 1500 3) 380 4) 1280 46. The IR absorption band that distinguishes between a primary amine and an amide is at 57. A reaction turbine has a discharge of 30 m3 /s 1) 3 45 0 c m–1 2) 2 20 0 c m–1 passing through it under a net head of 10m. –1 –1 3) 1 35 0 c m 4) 1 65 0 c m If the overall efficiency is 85%, the power developed in kW is 47. Generally in C, argv is an/a 1) 3400 2) 3450 3) 2940 4) 2500 1) array of character pointers 2) pointer to an array of character pointers 3) array of strings 4) none of the above

58.

If each of the resistances in the network shown in the figure is R, what is the resistance between the terminals A and B?

48. A digital gate can respond to an input signal in 1) about a second 2) about a hundredth of a second 3) a few billionth of a second 4) a few millisecond 49.

50.

51.

The time required for a pulse to decrease from 90 to 100 percent of its maximum value is known as 1) rise time 2) decay time 3) binary level transition 4) propagation delay period

1) R / 4 59.

Which memory is difficult to t interface with processor? 1) Static memory 2) Dynamic memory 3) ROM 4) RAM 60.

SAKTHI

E/TANCET-MBA-MCA-2005-08/mech-auto-aero-engg-2008/ts2

2

3) R

4) 2R

In the given circuit, the value of current I is,

1) 1 A

W h i ch o n e o f t h e f ol l o wi n g i s no t a characteristic of COBOL? 1) It is very standardized language 2) It is very efficient in terms of coding and execution 3) It has limited facilities for mathematical notation 4) It is very readable language

2) R / 2

2) 2 A

3) 4 A

4) 8 A  

A DC voltage source is connected across a series R-L-C circuit. Under steady state conditions, the applied DC voltage drops entirely across 1) R only 2) L only 3) C only 4) R and L combination ME - BASIC ENGINEERING AND SCIENCES - 2012

61.

62.

What would be observed if a DC shunt motor is started with an open circuited field? 1) the motor does not pick up speed but draws only a small current 2) the motor does not pick up speed but draws a large current 3) t h e m o to r p i c k s u p f a s t a n d ac q u i r e f ul l speed'while drawing large current 4) the motor picks up fast and acquires full speed  while drawing small current

1) 12.4 nm 3) 0.124 nm

Synchronous motor speed is controlled by varying 1) field excitation 2) supply voltage 3) supply frequency 4) both supply voltage and frequency

2) 1.24 nm 4) 0.0124 nm

69.

A screen containing two slits 0.1 mm apart is 1.20 m from the viewing screen. Light of wavelength = 500 nm falls on the slits from a distant source. Approximately how far apart will adjacent bright interference fringes be on the screen? 1) 12.0 mm 2) 6.0 mm 3) 500.0 nm 4) 1.20 nm

70.

I n t h e o p t i c al s p e c tr u m , t h e v i s i b le wavelength range is 1) 0.2 to 0.4 µ m 2) 0.1 to 0.15 µ m 3) 0.4 to 0.7 µ m 4) 0.7 to 1.5 µ m

71.

The theoretical strength of a defect free glass is 7 GPa. The breaking strength of the glass plate if it contains a 1 µ m-long surface crack (crack tip radius = 0.264) is 1) 57 MPa 2) 57 GPa 3) 80 MPa 4) 25 MPa

72.

An electron in the conduction band of an intrinsic semiconductor has an average energy of  1) (3/2)kT 2) (3/5)E F 3) E c  + 3kT 4) E c  + (3/2) kT

63.

AC current can not be measured directly by 1) hot wire ammeter 2) moving iron ammeter 3) moving coil ammeter 4) thermocouple type ammeter

64.

The breaking of atomic bonds along specific crystallographic planes occur in 1) ductile f racture 2) transgranular fracture 3) intergranular fracture 4) all of the above

65.

Below the Curie temperature, the crystal structure of BaTiO3  is 1) tetragonal 2) hexagonal 3) orthorhombic 4) cubic

66.

Which of the following are the two primary constituents of clays? 1) alumina and limestone 2) l i me s t o n e a nd c u p r i c o x i d e 3) silica and limestone 4) alumina and silica

67.

If a ceramic piece is desired that is dense and, in addition, is to experience very little or no grain growth during its processing, which of  the following powder pressing techniques 75. Two ideal cavities emit thermal radiation. The should be used? spectrum emitted by the first cavity is most intense 1) uniaxial pressing followed by sintering at a wavelength of 600 nm, and that of the second 2) isostatic pressing followed by sintering at 500 nm. Compared with the second cavity, the 3) hot pressing radiation emitted by the first cavity is 4) all of the above 1) more intense at all wavelengths 2) more intense at short wavelengths and less Electrons in an X-ray tube are accelerated by intense at long wavelengths a potential difference of 10.0 kV. If an 3) less intense at short wavelengths and more electron produces one photon on impact with intense at long wavelengths the target, what is the minimum wavelength 4) less intense at all wavelengths of the resulting X-rays?

68.

73. The superconducting state obeys the equations 1) ρ = 0 and B ≠  0 2) ρ = 0 and B = 0 3) ρ ≠   0 and B ≠  0 4) ρ ≠ 0 and B = 0 74.

A quantum-mechanical system initially in its ground level absorbs a photon and ends up in the first excited state. The system then absorbs a second photon and ends up in the second exited state. For which of the  following systems does the second photon have a longer wavelength than the first one? 1) a harmonic oscillator 2) a hydrogen atom 3) a particle in a box 4) a particle outside a box

ME - BASIC ENGINEERING AND SCIENCES 2012 – ANSWERS 3 1 ....... 4 4 1 ....... 1 5 1 ....... 2 6 1 ....... 2 7 1 ....... 1

32 42 52 62 72

....... ....... ....... ....... .......

4 2 4 4 1

3 3 ....... 4 4 3 ....... 3 5 3 ....... 2 6 3 ....... 3 7 3 ....... 4

3 4 ........ 4 4 4 ........ 3 5 4 ........ 4 6 4 ........ 1 7 4 ........ 2

SAKTHI

E/TANCET-MBA-MCA-2005-08/mech-auto-aero-engg-2008/ts3

3 5 ........ 2 4 5 ........ 3 5 5 ........ 2 6 5 ........ 1 7 5 ........ 2

36 46 56 66 3

....... 3 ....... 3 ....... 4 ....... 4

3 7 ....... 4 7 ....... 5 7 ....... 6 7 .......

4 2 4 3

38 48 58 68

....... ....... ....... .......

2 4 4 3

3 9 ....... 1 4 9 ....... 1 5 9 ....... 2 6 9 ....... 2

4 0 ........ 4 5 0 ........ 2 6 0 ........ 1 7 0 ........ 3

ME - BASIC ENGINEERING AND SCIENCES - 2012

DETAILED SOLUTIONS

33.

(4)

20 µ×6 = 20×4 20 × 4 µ=  = 0.67 20 × 6

I = MK2  = 200×50 = 10×103  kg cm 2 K.E =

= sin α  = 34.

10 m

Iw 2 2

90

(10 × 103 ) × (100 ) 2

10 12.8

35.

12.80 o

8m

2

 = 50×10

 wo =

 A  R   A 

Weight of ladder, w=20 N Length of ladder, AC=10 m Distance of lower end of ladder from wall, BC = 8 m In right angled triangle ABC,  AB =

10 m

G 20N

B

D 8m

C R C

57.

 AC 2 − BC2

10 2 − 8 2 = 36  = 6 m  As vertical wall is smooth , th ere will be no force of friction b/w ladder & wall. In the position of ladder, the ladder is just to slip. Hence the lower end C of the ladder will tend to move towards right and hence a force of friction b/w ladder & floor i.e. F A  = µ R C will be acting towers left Let R A  = reaction at A  R C = reaction at C µ = co-efficient of friction b/w ladder & floor at c F C = force of friction at c= µ R C Ladder is uniform and the weight of ladder (w=20N) is acting at the middle point of AC at G. The line of action of W will pass through line middle point of BC.

Hence distance CD =

×BC =

8

η  =

E/TANCET-MBA-MCA-2005-08/mech-auto-aero-engg-2008/ts4

2π × 200

p Pn pn = pQg Hn = 1000×30×9.82×10 = 2.946×106 P pn

p =  η ×pn = 0.85×2.946×106 = 2.5×106 = 2504 kW 68.

(3) Ek = = = E = E =

= 4.0 m

2 2 Resolving the force ver tically. We get R C = 20 N Resolving the forces horizontally, we get, R A  = F C = µ ×R C = µ ×20 = 20 µ Taking the moments of all forces abou t point C Clockwise moments = anticlockwise moments R A ×RB = 20×CD SAKTHI

=

(4)

η  =

=

1

2πN o

= 20.94 rad/s 60 60 Final speed, N = 160 rpm ∴  Final angular velocit y, 2πN 2π × 160 =  w = = 16.75 rad/s 60 60 Time t = 105 For uniform retardation,  w = w o+at or 16.75 = 20.94+α ×10 16.75 − 20.94 = –0.419 rad/s 2 α = 10 = – 0. 42 r ad/ s2

6

= 0.78 = 51.34

(4)

(2) Initial speed, No = 200 rpm

 λ

= =

eV 1.6×10–19 ×10×103 1.6×10 –15  J hf   hc

λ hc E 6.6 × 10 −34 × 3 × 10 8

1.6 × 10 −15 = 1.23×10 –10  m = 0.12375 nm 4

ME - BASIC ENGINEERING AND SCIENCES - 2012