January 2011 IBM Placement Paper:

1. In the case of a 70 MHz 1F carries for a transponder band width of 36 MHz; energy must lie between – MHz.

a.) 34 and 106
b.) 52. And 88
c.) 106 and 142
d.) 34 and 142

2. Radar used to eliminate clutter in navigational application is –

a.) Pulse radar
b.) Tracking radar
c.) MTI radar
d.) Mono pulse radar

3. The 1.55 mm windows is not yet in use with fiber optic systems because –

a.) The attenuation is higher than at 0.85 mm
b) The attenuation is higher than at 1.3mm
c.) Suitable laser devices have not yet been developed
d.) It does not lend itself to wavelength multiplexing

4. Pre-emphasis in FM systems involves-

a.) Compression of the modulating signal
b.) Expansion of the modulating signal
c.) Amplification of lower frequency components of the modulating signal.
d.) Amplification of higher frequency components of the modulating signal.

5. In a terrestrial microwave system transmission of signals is achieved through-

a.) reflection from the ionosphere
b.) line of sight mode
c) reflection from the ground
d.) diffraction from the stratosphere.

6. Casse grain feed is used with a parabolic reflector to

a.) increase the gain of the system
b). increase the bandwidth of the system
c.) reduce the size of the main reflector
d.) allow the feed to be placed at a convenient point.

7. In most microwave communication link rain drop attenuation is caused due to-

a.) scattering of microwaves by water drops of specific size.
b) scattering of microwaves by a collection of droplets acing as a single body.
c.) absorption of microwaves by water and consequent heating of the liquid
d.) absorption of the microwaves by water vapor in the atmosphere.

8. When a (75 – j40)W load is connected to a coaxial line of Z0 = 75 W at 6MHz then the load matching on the line can be accomplished by connecting-

a.) A short – circuited stub at the load
b.)An inductance at the load
c. )A short circuited stub at a specific distance from the load
d.)none of the above

9. When a signal of 10 mV at 75 MHz is to be measured then which of the following instruments can be used –

a.) VTVM
b.) Cathode ray oscilloscope
c.) Moving iron voltmeter
d.) Digital multimeter

10. Amplifier of class B has high theoretical efficiency of 78.5 percent because-

a.) It is biased almost to saturation
b.)Its quiescent current is low
c.)It’s output is an exact replica of it’s input
d.)It is biased well below cut off

11. If you type in the command nohup sort employees > list 2 > error out & and log off ,the next time you log in, the output will be

a) in a file called list and the error will de typed in a file error out
b) there will be no file called list or error out
c) error will be logged in a file called list and o/p will be in error out
d) you will not be allowed to log in
e) none of the above

12. In UNIX a files i-node ......?

Ans. Is a data structure that defines all specifications of a file like the file size,
number of lines to a file, permissions etc.

13. The UNIX shell ....

a) does not come with the rest of the system
b) forms the interface between the user and the kernal
c) does not give any scope for programming
d) deos not allow calling one program from with in another
e) all of the above

Ans. (b)

14. enum number { a= -1, b= 4,c,d,e}
What is the value of e ?

(a) 7
(b) 4
(c) 5
(d) 15
(e) 3

15. The very first process created by the kernal that runs till the kernal process is halts is

a) init
b) getty
c) both (a) and (b)
d) none of these

Ans. (a)

16. Output of the following program is
{int i=0;
case 0:i+=5;
case 1:i+=2;
case 5:i+=5;
default i+=4;

a) 0,5,9,13,17
b) 5,9,13,17
c) 12,17,22
d) 16,21
e) Syntax error

Ans. (d

17. What is the output in the following program
{char c=-64;
int i=-32
unsigned int u =-16;

a) Pass1,Pass2
b) Pass1,Fail2
c) Fail1,Pass2
d) Fail1,Fail2
e) None of these

Ans. (c)

18. The coupling that produces minimum interference with frequency response is-

a.) Direct coupling
b.)Impedance coupling
c.) R C coupling
d.)Transformer coupling

19. superconductor is a –

a.) A material showing perfect conductivity and Meissner effect below a critical temperature
b.) A conductor having zero resistance
c.) A perfect conductor with highest di-magnetic susceptibility
d.) A perfect conductor which becomes resistance when the current density through it exceeds a critical value

20. When an inductor tunes at 200 KHz with 624 pF capacitor and at 600 KHz with 60.4 pF capacitor then the self capacitance of the inductor would be –

a) 8.05 pF
b) 10.05pF
c.) 16.01pF
d.) 20.01pF

14. The Q of a radio coil –

a.) is independent of frequency
b.) increases monotonically as frequency increases
c.) decreases monotonically as frequency increases
d.) increases upto a certain frequency and then decreases beyond that frequency

15. When a generator of internal impedance and operating at 1GHz feeds a load via a coaxial line of characteristic impedance 50 ohm then the voltage wave ratio on the feed line is –

a.) 0.5
b.) 1.5
c.) 2.5
d.) 1.75

16. The coding system typically used in digital telemetry is –

a.) PPM (pulse position modulation)
b.) PAM (pulse amplitude modulation)
c.) PCM (pulse code modulation)
d.) PDM (pulse duration modulation)

17. Radiation pyrometers are used for the measurement of temperature in the range of –

a.) -2000C to 5000C
b.) 00C to 5000C
c.) 5000C to 12000C
d.) 12000C to 25000C

18. RF amplifier of an A.M. receiver is normally biased in –

a.) Class 'A'
b.) Class 'b'
c.) Class 'C'
d.) None

19. The value of gate voltage for the operation of enhancement of only N channel MOSFET has to be –

a.) High positive
b.) High negative
c.) Low positive
d.) Zero

20 .Consider the following expressions indicating the step or impulse response of an initially relaxed control system-

1. (5 – 4e-2+) u(t)
2. (e-2t +5) (u(t))
3 .V(t) + 8e-2t u(t)
4 . V(t) + 4e-2t 4(t)

21. . In a square, all the mid points are joined. The inner square is shaded.
If the area of the square is A, what is the area of the shaded area?

11. Two questions on basic angles i.e given a circle, a few chords or diameter is drawn etc.

12. If the following statements are given

@(a,b)= (a+b)/2
/(a,b)= a/b
*(a,b)= ab
If a=1, b=2 then find

i) /(a,(@(a,b),*(a,b)))

ii) */(a,@(*(a,b)))

13. If the following statements are given

(x#y) = x + y- xy
(x*y) = (x + y)/2
i) Find the values of x, y will satisfy this equation (x#y)#(x*y) < (x#y)
ii) Find the values of x, y will satisfy this equation (a*b)#(b*c)< (a#b)*(b*c)

14. Export PS1 results in(PS1 pwd)

a) primary prompt being your current directory
b) primary prompt and secondary prompts being the current directory
c) primary prompt prompt being your home directory
d) primary prompt and secondary prompts being the home directory
e) None of the above.