Posts Tagged ‘ Pattern

Solved Sample Puzzles For Infosys And Wipro Placement 16 January 2009 at 6:41 pm by Premium Blogger

Puzzles asked in 2008 Placement papers of Reputed IT companies like Infosys, Wipro, Satyam Computers, Tech Mahindra, Birlasoft, TCS, HCL and other MNCs.

1. You are given two candles of equal size, which can burn 1hour each. You have to measure 90 minutes with these candles.(There is no scale or clock). Also u r given a lighter.

Ans: 1. First light up the two ends of the 1st candle. When it will burn out light up one end of the second candle. (30+60=90)

2. Try the similar problem to measure 45 minutes.

Ans: First light-up the two ends of the 1st candle and one end of the 2nd candle. When the 1st candle will burn out ,then light up the both ends of the 2nd candle (15+30=45)

3. You r given a thermometer. What can u do by this without measuring the temperature?

Ans:
if u put thermometer into a tree it won’t grow anymore,will just die off

4. How it is possible to place four points that are equidistance from each other? OR U r a landscape designer and your boss asked u to design a landscape such that you should place 4 trees equidistance from each other. (Distance from each tree to the other must be same)

Ans: Only 3 points can be equidistant from each other. But if u place points in the shape of a pyramid then its possible

5. You are given a cake; one of its corner is broken. How will u cut the rest into Two equal parts?

Ans: Slice the cake

6. How will you recognize the magnet & magnetic material & non-magnetic material?

Ans: Drag one piece of material over another. There is no attractive force in the middle portion of the magnet. OR Get a piece of thread and tie up with the one bar and check for poles. If it iron bar then it moves freely and if it is magnetic bar then it fix in one direction according to poles.

7. If one tyre of a car suddenly gets stolen…. and after sometime u find the tyre without the screws how will u make ur journey complete

Ans: Open 3 screws, 1 from each tyre and fix the tyre.

8. How can u measure a room height using a thermometer?

Ans: temp varies with height. but its dependent on various other factors like humidity, wind etc.

9 What is the height of room if after entering the room with a watch ur head strikes a hanging bulb?

Ans: Oscillate the hanging bulb. Calculate the time period for one complete oscillation by Simple Harmonic Motion (SHM) of the handing bulb. Put it in the formula T=2 * 3.14 * (L/G)^1/2 L will be the length of the hanging thread. Add the L with ur height to get the height of the room.

10. Color of bear…. if it falls from 1m height in 1s.

Ans: We get ‘g’ perfect 10 which is only in poles…hence polar bear…color White

Latest / recent puzzles put / asked in Technical or HR interviews of IT companies placement question papers for freshers and on campus drives

11. How will you measure height of building when you are at the top of the building? And if you have stone with you.

Ans:
Drop the stone and find the time taken for the stone to reach the ground. find height using the formula s = gt*t/2 ( s = height, a= initial velocity=0, g=9.8m/s, t = time taken)

12. How wud u catch and receive a ball in same direction? (Dropping is from north and receiving from bottom not accepted, as it is 2 directions)

13. 25 statements given. Some tell truth, some false and some alternators. Find out the true statements.

14. Can u make 120 with 5 zeros?

Ans: Factorial (factorial (0)+factorial (0)+factorial (0)+factorial (0)+factorial (0)) = 120

15.There are three people A, B, C. Liars are of same type and Truth speaking people are of same type. Find out who is speaking truth and who is speaking false from the following statements:

a) A says: B is a liar.

b) B says: A and C are of same type.

Ans:
lets assume A is speaking truth. It means B is a liar then it means A and C are not of same type.

16.5 swimmers A, B, C, E, F and many conditions of their positions like there are Two b/w A & F, B doesn’t win etc the question was to find who was b/w like E & D?

17. in a race u drove 1st lap with 40kmph and in the second lap at what speed u must drive so that ur average speed must be 80kmph.

18. You have to draw 3 concentric circles with a line passing thru their center without lifting hand.

Ans:
Start the line complete one circle move inside circles along the line and then draw second circle. Like wise rest.

19. A rectangular paper is there. At a corner a rectangular size paper is taken from it. Now you have to cut the remaining paper into two equal halves.

Ans:
try it on the paper. You must fold the part that has complete paper and select Half of it and then fold the part that cut and selects half of it and then cut along the folding.

20. Value of (x-a)(x-b)………..(x-z)

21. There are 9 coins. 8 are of 1 gm and 1 is of 2 grams. How will you find out the heavier coin in minimum number of weighing and how many weighing it will need?

Ans:
2 weighing ( Divide the number of coins into 3 parts at each weighing)

+ ABB Placement Papers By Premium Blogger 08 January 2009 at 5:46 pm and have No Comments

TECHNICAL PAPER-40 QUESTION, 45- MINUTES

(1)in a ckt. We r giving voltage of 50 Hz as well as 60. then what will be  the resultant frequency.

(a)less than 50     (b) more than 60    (c) in between 50 & 60
(d) none……….according to our conclusion answer will be none because if  we apply two frequency component resultant frequency we can not say with  such an ease’s should confirm the answer

2.In a ckt a single resistor is connected across a d.c. source, what will be  the effect on current in first resistor if we connect one more resistance in  parallel with earlier one….

Answer.. no change since it is a parallel combination.

3.why we don,t like flashover in transmission line (t-line)-  (a ) it may create earth fault(b )it reduces the life of insulator…..
Read something about flashover & puncture.

4.total no of strands in a acsr conductor is 81, then what is the no. of  conductor in its outer layer….(a)36 (b)18 (c)24…….

5.Two questions based on p.u. calculation like , p.u. calculation is given  with respect to some old base and u have to calculate it with reference to  new base.  (new resistance/old)=(mva new /mva old)*(old voltage/new voltage)2

Other question is based upon transfer of p.u calculation in transformer i.e.  how base changes when we we move from primary to secondary or like wise.read  some more on p.u calculation.

6.which table is referred for sag calculation-

(a)stringing chart……answer

7.in a R-L ckt a ac voltage is applied , such that instantaneous power is  negative for 2ms, then what will be the power factor.

(a) 9 deg, (b) 18 deg, (c) 36 Deg………..

8. In an incandescent lamp

(a) luminous intensity is more than non-luminous intensity    (b) ,, ,, ,, less ,, ,, ,,

Ans: Since efficiency is less than 100%, hence ans is (b), u should confirm it further.

9. In which motor no-load to full-load diff. is lowest

(a) series motor,     (b) shunt motor,     (c) Compound motor

Ans:
(b)

10. In a 60Hz induction motor full load speed is 850 rpm then what is the  Synchronous speed. (a) 900 rpm, (b) 950 rpm, (c) 1600rpm…

Ans: (a)

11. A sync. Motor is running at synch. Speed, if al of sudden D.C.  excitation is removed, then

(a) it will rotate at slip speed,  (b) it will stop, (c) it will continue to  rotate at sync. Speed

Ans: (a), because actually it will acts as Induction motor.

12. A transmission line is designed for 50Hz, 440KV. If we want to transfer  power at 60Hz, 440 KV, then the power transfer capability will

(a) decrease,     (b) Increase,     (c) None

Ans: (a) …as P=( |Vt| |Ef| sin (delta) ) / X, where (delta) is torque angle.

13. Increased rotor resistance in rotor ckt of induction motor is related  with

(a) high starting torque,  (b) more speed variation,…………………Ans: (a)

14. In the formulae E = 4.44 f N ?, ? is

(a) Avg value, (b) Rms value,     (c) Maximum value…………………Ans: (a)…[confirm it]

15. Voltage & current in a ckt is given by V= V1+j V2 and I= I1 +j I2, then rms power is…….(refer book by Administrator on NETWORK ..)

16. Input impedence of MOSFET is

(a) more than BJT……..(Ans)

17, 18. Remember truth table of AND, NOR, NAND, OR, EX-OR ETC…

19. Conversion of Binary number into Equivalent decimal No.

20. Megger is used for the measurement of (a) Insulation resistance, (b)Conductor resistance………….Ans: (a)

21. Form factor for sinusoidal as well as DC

22. Formulae of Regulation (Vs- Vr)* 100/ Vr, then transmission line is

(a) short transmission line, (b) long,  (c) medium……………….Ans: (a)

23. Improvement in power factor reduces

(a) power consumed by consumer, (b) power generation, (c) both a & b………..Ans: (c) [Confirm it]

24. Read about field test of Series Motor…

25. No-load test for Synchronous motor, the graph is drawn

(a) stator open ckt emf Vs field current…………………………………(Ans: a)

26. An AC voltage of 50Hz is impressed in a resistive ckt, the oscillating  power has a frequency (a) 50 Hz, (b) 100, (c) no oscillating power is there  in resistive ckt……Ans: (a)
27. Insulation used in transformer ___________leakage flux.

(a) increases, (b) decreases………...Ans: (b)

28.After rain what happens to Insulator (a) break-down strength of Insulator  decreases, (b)Arch length reduces, ……Ans: (b)..[Confirm it]

29.Diversity factor helps to …………(what ?)  [Read diversity factor, load factor, Reserve capacity factor in depth, with calculation]

30. Why capacitance is shown as a Shunt element in analysis of transmission  line

(a) it is between Conductor & earth, (b) because Admittance is used for  calculation of capacitive reactance…………………Ans: (a)

31. B-R-Y sequence is followed in three phase system, if phase voltage in  B-phase is Vm sin 100, then the phase voltage in R-phase would be (a) Vm  sin (-20)            Ans: (a)

32. In a particular ckt I = Im Sin (wt -270) and V = Vm Sin wt, then type of  ckt is (a) pure resistive ckt

33. In a L-R ckt energy lost = 2000 W, energy conserved = 500W, then what is  the time constant………..Ans: time constant = L/R = 0.5

34. In electro-dynamometer A,meter & wattmeter the type of scale is

Ans:Non-uniform
35. For the same current carrying capacity corona loss of ACSR will be  ________than copper conductor.
(a) more, (b) less, (c) equal.     Ans: (b)

36. A R-C ckt , supplied with DC, a bulb is connected across the Capacitor,  then what happens to the illumination, if we change the capacitance.

Ans: No change at all

37. Read about surge impendence of over-head and under-ground cable, Surge  impedence formula = sqrt(L/C)

[N.B] We are not mentioning the options in sequence, and do not think  that ans for the most questions is option (a). Read all options very  carefully as all are very close to each other.

QUANTITATIVE PAPER + PCM paper

45 Questions    (45 minutes)

1. About 10 quanti questions ( based on Mixture, Work etc. of very easy  type)

2. What is GDP ?

3. Vector algebra, codition for Co-planer vector etc.

4. Gravitation, geo-synchronous satellite( it,s hight, orbit , radius etc.), escape velocity, how g (gravitational accln) varies, about  gravitational potential.

5. Basic electricity and Magnetism—-Biot-savart law, current carrying  conductor properties.

6. Nuclear physics, Bohr,s constant, and Other theories related .

7. Problem based on VIBGYOR , how wave length and frequency is varying.

8. Questions based on Plank,s Theory, E =hv

9. V=u + at , V2=u2 + 2as and W = mgh  questions based on above theory

10. Faraday,s laws of electrolysis, m = Zit

11. Heat conduction problem.

12. Co lour-coding of resistor (BBROYGBVGW)

13. How velocity of light changes in different medium while frequency remain  unchanged.

14. statistics , calculation of mode, co-efficient regression (3-4  Questions)

15. f(x) = Sin x + Cos x, find the maximum value of the function…….Ans: sqrt (2)

16. Formulae for parallel plate capacitor and force between plates