TATA Elxsi Placement Paper

Tata Elxsi Questions 

1. Problem on lissojous pattern: in x-y mode if vlg applied to x-axis is 2 sinwt then what is the vtg to be applied to y-axis so that we observe the following pattern on the cro : [angle b/n x-axis and the diagonal line is 45degrees] ans is 2root 2 sin (wt +45)

2. What is the resolution of an adc : vref/(2 pow n).

3. Some circuit is given with two f/f s ,what is that circuit? Ans may be shift reg

4. Spatial to temporal converter is ? (a) shift reg ( b) counter (c ) adc ans may be adc 

5. Darlington is used for _____ ans high current gain

6. Some circuit with nand gates is given ,what is that circuit ans is xor                                   

7. A wired circuit with some nand gates is given asked the function of that circuit

8. An opamp circuit is given asked to find the transfer function of it ( I think its an ideal integrator circuit)

9. A pole zero pattern of an impedance function is given . it has a conjugate pair of zeros and a conjugate pair of poles ,then what elements does the impedance consists of? Ans LC elements

10. Most computers wont use floating point arithmetic .why        a.costly b. slow c. cant

11. Bit-slice processor mean …… ans used for shift ,masking of bits 

12. ac motor used in servo applications is (a) single phase induction b.2 phase induction c. 3 phase induction

13. TV resolution depends on a. bandwidth 2. detector c. no. of frames /sec

14. Equalizing pulses are sent in tv during a. horizontal blanking b. vertical blanking ……….

15. cdma is not suitable for satellite communication . why ? ans may be complexity of operation 

16. Given some waveforms and asked that which of the waveforms will have odd harmonics of sine terms

17. Asked for two’s complement of a number

18. maximum signed no. represented by a 8 bit computer

19. A chip has a capacity of 256bits,to implement a 1KB capacity how many chips are required ans 32

20. ecl operates in ____ and ____ regions of the transistor 

21. Given a transient circuit ,asked for time constant while charging and discharging 

22. He had given 4 statements about a f/f and asked which of them are correct 
    1. it can store a bit 2. jk f/f have rat race when storing a 2 bit info 3. master slave is used to store a 2 bit info 
    4. d f/f used as a latch for multiplexing operations 

23.  Venn diagram is given and asked to write expression for the shared portion in it                        

24. cb and ce are ____ biased when transistor is in saturation 

25.  condition for nyquist rate

26. carry look ahed adder is 1.fast 2. requires more h/w 3. costly

27.  ideal power supply will have a. zero internal resistance b. more o/p resistance c. less o/p resistance 

28. A problem on cro and probe interface i.e design of an attenuator for the cro probe (formula for it is R1 * c1 = R2 * C2 )