TATA ELXSI-Placement Paper
Hi all ,there were two rounds 1)TECH(30 ques,30 mins)2)APTITUDE(30 ques,30 mins)
TECH QUESTIONS(Electronics & TC):
(GATES ARE SHOWN AS :e.g .inverter is shown as
1)CMRR is given=
Differential gain is given=
Inputs:
+ve end=2v,-ve end=1v of the OP-AMP
Find the output voltage?
TATA ELXSI Latest Fresher Engineer Placement Sample Question Paper 3 2004
2)CRO is in X-Y mode.Sinusoidal inputs have 90degrees phase difference between them.
What will appear on the display?
a)circle b)line c)ellipse d)triangular wave
3)Which has least propagation delay?
a)ECL b)TTL c)RTL d)CMOS
4)In a ripple counter how many change in states happen when count changes from7 to 8?
a)1 b)2 c)3 d)4
5)Max. no. of variables that can be represented in K-MAP?
a)3 b)5 c)7 d)none of these
6)How many comparators are required in a n-bit flash ADC?
a)2^(n-1) b)(2^n)-1 c)2^n d) n
7)What is an EEPROM?
a)Programmable transistor
b)Transistor
c)SRAM
d)
8)Time period of input voltage=8ns. / Find the duty cycle of Vout.
Vout(0 ns.)
Vin
9)Voltage across one capacitor is V volts.
Another cacitor is added at its one end(now the two are in series).
What is the voltage across their ends?
a)V b)V/2 c)2v d)none of these
10) In an SCR why silicon is used?
a) available easily
b) has much less reverse saturation current than Germanium
c) has greater reverse sat.current than Ge
d)
11)Output=?
A
B OUTPUT
C
a)A¡¯+B¡¯+C
b)A+B+C¡¯
c)A(B¡¯+C¡¯)
d)B¡¯+C¡¯+A¡¯
12)There was a question using transmission gates.Three inputs were A,B,C.Answer was
(A+BxorC)
13)How to get the characteristic figure changed from 1 to 3?(characteristic diagram)
Vout 1 2 3
Vin
a)By increasing gate width of NMOS
b)---------do----------------- of CMOS
c)By increasing gate voltage
14)Find propagation delay?
Vin Vout
a)200Hz b)150Hz c)5Hz d)2Hz
15)A diagram was given to identify?
a)Synchronous counter
b)Ripple counter
c)Shift register
d)None of the above
answer was sync. Counter
16)Find Va?and Ia, Ib?
11K§Ù Va 43K§Ù
Ib
12V Ia 22K§Ù 5V
GND
17)Find ammeter current Ia? 10§Ù
+
10V Ia Ammeter,Ra=1§Ù
_
a)10V b)9.09V c)11.01V d)0.9V
these options may be wrong.
A
1
This acts as a:
B a)OR
b)XOR
c)AND
d)NOR
A¡¯
A
F
A¡¯
19)At t=0 if position is changed from 1 to 2 ,find the voltage across 1K§Ù?
2
1
V
4V
a)4V b)2V c)1.5V d)none of these
20)Find thevenin voltage and resistance across A and B.
A
+
10V
_ Ammeter
B
21)how will be the output voltage across R ?
Diode
+5V sine input
R§Ù
2V
GND
a) b)
d)
C)
Ans.C L
22)what is this?
R
Vin
Vout
a)Integrator b)Differentiator c)Antilog differentiator d)Log differentiator
23) 1/1
0/0
0/1
Flip-flop state diagram question.What does the above represent?
24)What is this?
Vin
Vout
GND
a)Squaring device b)Divider c)Square root ckt d)
25)How will be the output vs. input graph if Vin=10V,sat voltage of OP-amp is 14V?
R 2R
Vin
Vout
GND
a) b)
20V
-14V
c) d)
-20V
