Monday, January 10, 2011

Delphi Placement Paper ( Technical)

1.machine tool drives are generally given in:

a) arithmetic progression b)geometric progression
c) harmonic progression d)none of the above

2.finite element analysis is used in

a) accurate measurement b)stress analysis
c)metallurgy d)none of the above

3.coolant is generally not used while machining

a) low carbon steel b)high carbon steel
c) cast iron d)alloy steel

4.Machinability of steel is improved by the presence of

a)nickel b)tungsten
c)sulphur d)chromium

5.negative rake angle

a)increases cutting force b)decreases cutting force
c)no effect on cutting force d)none of the above

6.the hardest tool material used is

a)coated carbide b)high speed steel
c)boron nitride d)diamond

7.stick slip phenomenon is associated with

a)spindle rotation b)belt drives
c)slide movement d)none of the above

8.Gear hobbing is

a)shaping process b)generating process
c)forming process

9.cutting speed of H.S.S tools while cutting low carbon steel

a)40m/min b)250m/min
c)500m/min d)none

10.cutting speed of carbide tools while cutting low carbon steel

a)40m/min b)250m/min
c)500m/min d)80m/min

11.straightness that can be achieved over a length of 300mm by grinding

a).005 -.01mm b)0.1-0.2mm
c)0.05-0.1mm d)0.5-0.8mm

12.the circularity that can be achieved by finish turning on a standard centre lathe is

a)0.005-0.008mm b)0.0-0.08mm
c)0.1-0.2mm d)0.2-0.3mm

13.honing can correct

a)oviality b)taper
c)straightness of bore d)axial curvature

14.Machine tool sliding surfaces are finish matched by

a)surface grinding b)fine milling
c)slide way grinding d)scraping

15.Close sliding fit is given by

a)H7/g6 b)H7/h6
c)H9/p6 d)H7/k6

16.60H6 can be achieved by

a)turning b)boring
c)drilling d)internal grinding

17.The displacement accuracy which can be achieved on a jig boring machine

a)5/µm b)50/µm c)100/µm

18.Hardness value in cast iron can be measured in

a)shore b)BHN c)Rockwell d)none

19.Auto collimator is used to measure

a)dia upto 0.001mm b)lengths
c)straightness d)Involute error

20.Surface finish is measured by

a)comparator b)planograph
c)sprit level d)none

21.The outside diameter of a 20 teeth 3 module gear is

a)54 b)60 c)63 d)70

22.Herring bone gear is used for

a)High speed transmission b)noise free transmission
c)Better load transmission d)none

23.In a right angle transmission by helical gears, the hand of the helix of the gears are

a)same b)opposite c)Immaterial d)none

24.Worm drive is always self-locking

a)True b)false

25.Most hydrostatic bearings normally work under

a)constant flow system b)constant pressure system
c)constant temperature system d)constant volume system

26.Ball bearings are not generally used in crank shafts of automobiles because

a)of high cost b)of high speed c)cannot be assembled d)none

27.Bronze is used in journal bearings essential to

a)reduce friction b)reduce heat
c)eliminate oxidization d)eliminate seizing

28.The spindle of high precision cylindrical grinder is mounted on

a)Ball bearing b)Taper roller bearing
c)Hydrostatic bronze bearing d)needle bearing

29.To accelerate the flow of gases

a)nozzle is used b)diffuser is used
c)dia of pipe to increased d)none of these will help

30.Hydraulic accumulator

a)acts as an accumulator b)acts as a storage for hydraulic energy
c)acts as a pressure relief d)none

31.When ice which is floating in water, melts, does the level to water

a)go up b)go down c)remain the same.

32.Hammer blow in pipe happens due to

a)friction in pipes b)change in temperature
c)stoppage of flow d)none

33.Temperature rise in fluid flow causes

a)reduction in viscosity b)increase in viscosity c)no effect

34.Ratio between velocity of sound and velocity of any object is

a)prandtl number b)Reynolds number
c)avagadro's number d)mach number

35.Cavitaion effect in flow occurs due to

a)excess pressure b)excess temperature
c)excess flow d)none

36.In electrical locomotives ultimate transmission is by

a)AC Motor b)DC Shunt Motor
c)DC Series Motor d)Synchronous motor

37.Four beams of identical sections and lengths are made of cast iron, aluminium,steel and hardened steel. The beams are fixed at both ends; for a uniformly distributed load which will deflect least

a)cast iron b)aluminium c)steel d)hardened steel

38 . Geneva mechanism is used for obtaining

a)Intermittent motion b)accelerating motion
c)continuous motion d)none

39.Corioles component is associated with

a)Displacement b)acceleration
c)velocity d)none

40.Effect of increase of outside diameter of a helical compression spring on its rigidity is

a)increased rigidity b)decreased rigidity
c)no effect d)dry friction

41.Jominey curve is related to the study of

a)hydraulics b)thermodynamics
c)electrical d)none

42.TTT diagram is used in

a)surface finish b)heat treatment
c)stress analysis d)thermodynamics

43.Mehanite is the name given to a type of

a)alloy steel b)granite
c)nodular cast iron d)cast iron

44.Unwanted impurity in molten aluminium is

a)oxygen b)carbon dioxide
c)nitrogen d)hydrogen

45.Hardness in steel is a s a result of

a)martensitic structure b)pearlitic structure
c)leduburetic structure d)austenitic structure


46.piston of an IC engine is made out of

a)cast iron b)steel casting c)beryllium alloy d)aluminium alloy

47. The crank shaft of a 300 HP IC engine is

a)hot forged b)shell moulded

c)cold forged d)obtained through investment casting

48. A 6kg ball is suspended from two wires of equal length. The angle between the wires is 90 degrees. What is the tension in each wire?

49. A 523 kg experimental rocked sted can be accelerated from rest to 1602 km/h in 1.82s. what net force is required?

4.6X106N
4.6X105N
1.6X106N
1.3X105N

50. A force that averages 984N is applied to a 0.42kg steel ball moving at 13.8 m/s by a collision that lasts 0.027s. if the force is in a direction opposite to the initial velocity of the ball, what is the final speed of the ball?

51. a stone initially at rest is dropped over the edge of a very tall building. Taking g as 10m/s2 , what was the change in the speed of the stone building during the 4th second?

10m/s
30m/s
15m/s
40m/s

52. how long will it take a 2000w motor to lift a 320kg container vertically upwards for 26m?(g = 9.8m/s2)

53. a collision between two isolated items will in generally conserve
a. the total kinetic energy and the total momentum of the system
b. the total kinetic energy but not the total momentum of the system
c. the total momentum but not the total kinetic energy of the system
d. the momentum of each object
what is the force exerted on a submarine window of 2m2 area, if the submarine is at a depth of 2km below the surface?(the density of sea water is 1.03X103 kg/m3)

54. How many of the following statements are true:
a. the buoyant force on a body depends on the shape of the body
b. the buoyant force on a body always acts in the same direction
c. the buoyant force on a body depends on the mass of the body
d. the buoyant force on a body depends on the density of the fluid surrounding the body

55. A body partially floats with 2/3rds of its volume under the surface of a fluid. If the density of the fluid is X kg/m3, what is the density of the body?

a)3/2 X kg/m3 b)2/3 X kg/m3
c)14.7 X kg/m3 d)0.15 X kg/m3

56. how many atoms are present in a mole of CH4 ?
(avagadro's number = 6.023X1023 /mole)

a) 1.2X1024
b) 3.01X1024
c) 1.2X1023
d) 6.023X1023

57. A power station generates 500MW of power and exhausts 800MW as waste heat into the environment. What is the efficiency of the power station?

a) 61.5%
b) 38.5%
c) 62.5%
d) 23%

Friday, January 7, 2011

Windows Cell Phone Operating System,MS Windows OS on ARM Chips

Microsoft developing Windows for phone chips
Microsoft Corp. confirmed Wednesday(5th Jan 2011) that it is developing a version of its main Windows operating system that will run on cell phone chips, providing an alternative for the first time in many years to the chips based on Intel technology.


The new version could take advantage of the power savings provided by cell phone chips, and give Microsoft a better chance of gaining a foothold in the emerging world of tablet computers. Apple Inc.'s hit iPad tablet runs on a cell phone-type chip, which is part of the reason it can last 10 hours on one charge.

Thursday, January 6, 2011

What Is Transmission Security?

What Is Transmission Security?


Transmission security is the capability to send a message electronically from one computer system to another computer system so that only the intended recipient receives and reads the message and the message received is identical to the message sent. The message would not be identical if it was altered in anyway, whether transmitted over faulty channels or intercepted by an eavesdropper. Transmission security translates into secure networks. Although many people regard networks as computers connected by wires, this definition of a network, while technically correct, misses the point. Rather, networks are transmitted data, the data flowing over wires.

All transmissions can be intercepted. And the cautious user looks at all transmissions as if they will be intercepted. You can minimize the risks of transmission interception, but you can never, under any circumstances, completely rule it out. After all, it is people who design and put wires in their place, and people can get to them. Accessing wires is somewhat comparable, although much more difficult, to accessing a transmission sent over airwaves, as on a CB radio. For example, as a ham, you may have a message intended only for other hams. Although hams are the main communicators on these frequencies, anyone with the right radio equipment can tune in and listen, so it's likely your message will be received and heard by other listeners who pick up the frequency, whether you want them to hear it or not.

Similar risks occur with cellular phones, even though most transmission takes place over wire and not air. One risky transmission occurred between Prince Charles and his mistress Camilla Parker Bowles when an eavesdropper intercepted a now infamous cellular phone conversation between the two.

So, like it or not, networks are our transmissions. If you ascertain that security is too high to risk over networks and you decide not to transmit over networks, throw your computer systems away; you've wasted your money. Unfortunately, transmission interceptions are inevitable; it's likely they will occur at times. Designing a 100 percent transmission-secure network is akin to designing a car that can't be broken into; no matter how secure the car is, someone can always break the windows. This doesn't mean you should sit back and wait for the interception, however; instead, build your system to deter people from attempting to break in, and make it costly for the hacker to enter.