**iSoft Placement Question Paper_26.**

what is zeroth law ?

why should we place 9KV lightning arrestors in 11KV** substation ?**

How to calculate % Impedence?

what is meant by dielectirc medium? what is the dielectirc value of air and water???

what is DAR test?

what is the value of prandtl no. for air?

1) Moore model of DFF?

2) Which of the following filter has steep roll-off characteristics?

(A) Butterworth filter (B) Chebyshev filter (C) Bessel filter (D)–

ans: B

3) The architecture of DSP processor———

(A)Havard (B) Von neumann (C)…(D)..

ans: A

4) If the input frequency to a 6 stage ripple counter is 1000MHz then output

frequency at 6th stage_______

5) Minimum number of 2 input NAND gates required to realise the fn. AB’+CD’+EF’

ans: 6

6) What will exit() fn. in C will do?

7) goto command in C will cause the program to jump to—-

ans: Label

8) VSWR is given then asked to find out reflection coefficient

9) The relation between power in FM signal and modulation index——–

10) If two signals are AM modulated with modulation indices of 0.3 and 0.4 what will

be the modulation index of combined signal?

ans: Calculate using 1/M=(1/m1)+(1/m2)

11) If n stage pipelining is used in aprocessor, then what will be the speed

improvement over nonpipelined processor?

(A) same (B) n (C) n! (D) 2n

12) One circuit is given (That was a Voltage Doubler using op-amp) and asked to

Identify that…

13) Which one of the following memory has fastest write time?

(A) Flash (B) EEPROM (C) EPROM (D) None of these

14) In EEPROM data is stored in____

(A) Cross coupled Latch (B) Capacitor (C) floating gate transistor (D)–

15) Which technology is faster?

(A)Bipolar (B) MOS (C) CMOS (D) ..

16) Memory access time, cache access time, hit ratio are given, Asked to find out

Average memory access time

17) If the probability of getting a job for A is 1/3 and the probability of getting a job

for B is 1/4 then the probability of getting a job for A or B will be____?

18) One transfer fn As4 + Bs3 + Cs2 +D=0 (I dont remember the values of A,B,C,D

) is given, Asked to find out whether the system is____

(A) Stable (B) Unstable (C) Marginally Stable

19) For implementing D flipflop using RS flip flop, the extra component needed

is____

(A) AND gate (B) OR gate (C) NOT gate (D) NOR gate

20) The output of an 8 bit DAC is 1Volt when the input is 00110010, then the full

scale output of the same DAC will be____

ans: 5.1 V (Hint: 1/50*255)

21) Fastest ADC is___

(A) SAR (B) sigma- delta (C) flash (D)…

22) The operating point of Class-B amplifier will be at_____

(A) exactly at cut-off region (B) inside saturation region (C) inside cut-off region

(D) middle of active region

23) For an N bit ADC , the number of comparators needed___

(A) N (B) 2N (C) 2N -1 (D) 2N-1

24) De-emphasis circuit is used for_______

ans: Attenuating high frequency components

25) The laplace transform of e-2t _____

Ans: 1/(s+2)

26) The magnitude of 1+cos x+j sin x____

Ans: 2 cos (x/2)

27) A circuit is given in which the capacitor (1uF) is initially charged to 12V, At t =

0, one switch is closed so that another capacitor of capacity 1.5uF comes in parallel

with the first capacitor, then in steady state what will be the voltage across them? (

Visualize the circuit, as I can not draw the circuit since the editor is not supporting it)

28) Alpha of a transistor=0.99, Ico=1uA, Ie=1 mA, Ic=?

29) If the input given to an inductor is delta(t) (ie: =1 when t=0 and ,=0 otherwise)

then the current will be___

(A) infinity (B) -infinity (C) 1 (D) 0

30) For implementing Band pass filter using High pass filter(Cutt off freq=Fh) and

Low pass filter (cutt off freq= Fl)_____

(A)Fh=Fl (B) Fh>Fl (C) FhP2>P1>P3

45 The bulb having weight 150N supported by two ropes and attached to the walls

having angles 45º & 60º. Findout the reaction forces in the ropes ?

This is related to Lamis theorem

46 A hollow sphere of radius r . A particle is moving with coefficient of friction

1/[3]½ inside the sphere from wall . which height will it become rest?

47 The disc is resting on the rough wall by a rope tied at the center . The rope

makes angle with the wall around 30º. The tension in the string is ———-than the

weight of the disc. more

48 A railway wagon containing partially full of water. Which angle—————-

49 Findout the graph between discharge [Q] in the x-axis and head [H] in the y-axis-

———

50 In welding pitch dimension is limited to———————-

51 The composition of inconel alloy——————-

52 There is a heat transfer between two walls having thickness and conductivities k1

& K2 respectively. The linear temperature profile of first wall is more steeper than

the second wall . Findout the ratio K1/K2 ———————

a) >0 b) <0 c)=0 d) the given data is insufficient 53 The max shear stress developed in solid circular shaet is 100 MPa . Calculate the max normal stress developed in it? ?????? 54 This question related to welding ————- 55 Bearing liner————————- a) Babbit metal b) Gun metal 56 Electrical resistance material ————–Nichrome 57 This question related to radiation 58 A sun emits 1150K at 0.5_. A furnace emits 300k from small door ————– 59 In the simple pendulum , the maximum amplitude depends on ——————- increase in length 60 The fuel flow increases if————————- a) exhaust valve burnt b) filter choke c) silencer choke 61 The jet propulsion depends on————- a) jet velocity b) weight ratio 62 What is the condition for perfect frame————————————- 63 Depth of cut can be increased by———————– 64 The workpiece can be held in—————– 65 This is related toNucleate boiling 66 What is the expression for Reynolds number in terms of diameter of the pipe…………..Re =?VD/_ 67 Air conditioning means————— a) cooling & heating b)dehumidifying c) removing impurities from air d)all 68 Fibrous fracture occurs in ———————— a)brittle fracture b) ductile fracture c)shear fracture d)none 69 In laser beam machining , the workpiece should be————– a)absorbed by all the rays b) reflected by all the rays 70 Foam and coke are good insulators. Why?———————– a)less density b) 71 Gold property—————— a)good conductor b)good insulator 72 In lathe , the workpiece can be held in ————————————– a) live center b)steady rest c)3-way chuck d)4-way chuck 1) output resistance of ideal OP AMP is:- a) 0 b) 1 c) infinite d) very high ANS: a) 0 2) waveguide acts as:- a) LPF b) HPF c) BPF d) BRF ANS: b) HPF 3) quality factor of series RLC ckt. increases with:- a) increase in R b) decrease in R c) doesn’t depends on R d) none of these ANS: b) decrease in R. 4) energy stored in capacitor is given by: a) CV b) 0.5CV c) CV2 d) 0.5CV2 ANS: d) 5) CMRR of an OP AMP is given as 80db and Ad is 20000.Value of Acm will be:- a) 4 b) 8 c) 2 d) 1 ANS: c) 2