1. For NOR ROM shown Resistance per cell = 100Ω , Wire Capacitance/cell and Gate capacitance/cell are 1.28pF and 18.72pF, what is the delay (for the word line) of the distributed RC-line of dimension 256 x 256.
a) 2nsec
b) 131 usec
c) 49.8 usec
d) 1872 psec
2. For a JK Flip Flop the input J1=J1J2J3, where J1 =1011011, J2=0111010, J3=1111000 and K-KIK2K3, where K1=0001110, K2=1101100 K3=1010101. Initially Q=0 and there is one clock pulse for each bit time. Find the output Q?
a) 0110110
b) 0011000
c) 0010110
d) 0110010
3. Consider a Hartleys Oscillator where L1 = 1mH and L2=2mH, C=10uF. What is the frequency of oscillation? Now if C is increased 4 times, whereas L1 and L2 are changed by a factor of 8 and 1/2 respectively, what will be the new frequency of oscillation?
a) 112.31 Hz , fnew= 104.6 Hz
b) 103.1 Hz , fnew=99.7 Hz
c) 918.88 Hz , fnew=530.5 Hz
d) 126.67 Hz, fnew=125.2 Hz
4. The resistivity of an n-type silicon sample is 10 Ohm-cm. What is the donor impurity concentration if the mobility is 1000 cm2/V-s. Assume T = 300K.
a) 100 x 10^12 cm-3
b) 6.25 x 10^19 cm-3
c) 6.25 x 10^14 cm -3
d) 9.9875 x 10^14 cm³ -3
5. The reference voltage of a 6 bit R-2R ladder digital to analog converter is 7 V. Calculate the value of analog output voltage for an input of 010101.
a) 2.296875 V
b) 3.976595 V
c) 1.470235 V
d) 4.592685 V
6. If the current state (Q0Q1Q2Q3) of the following counter is 1000 then find out the output (Q0Q1Q2Q3) after 90 clock pulses.
a) 1110
b) 1100
c) 1000
d) 1111
7. Following set of instructions are executed on an 8085 Microprocessor. What is the final content of the accumulator? (carry is reset)
MVI A, A9H
RRC
MOV B, A
RRC,
ADD B
a) FE H with C=0
b) FF H with C=1
c) FF H with C=0
d) FE H with C=1
8. Calculate the value of Vout. (VBE of Q transistor =1.2 V)
a) 1.5
b) 1.2
c) -1.2
d) -1.5
9. What is the output of the following program?
Module abc(x,y,z);
Output z;
Input x,y;
Assign y=(X'+XY');
Endmodule
a) X+Y'
b) X'+Y'
c) X+Y
d) X'+Y
10. The delay of the 1, 2 3, 4 gates are 7, 11, 13, 19 microseconds respectively. For certain values of x and z, together with certain transition of y, a glitch is generated for a short time, after which the output assumes Its correct value. Calculate the duration of the glitch. (Assume the wire delays are negligible).
a) 18 microseconds
b) 5 microseconds
c) 7 microseconds
d) 24 microseconds
11. If B= 11011 ,A <= B SRL-2 what is the content of A after the shift operation?
a) 00110
b) 01111
c) 01100
d) 11110
12. Calculate the resistivity of intrinsic silicon if the value of intrinsic carrier concentration (ni)=1.3x10^16/m3,electron mobility (un)=0.124 m^2/V-s hole mobility (up)=0.032m^2/V-s.
a) 3.086 x 10^3 Ωm
b) 7.112 x 10^3 Ωm
c) 5.786 x 10^3 Ωm
d) 9.453 x 10^3 Ωm
13. A 8V zener diode has knee current of 20mA and is supplied with a voltage of 12V. If Rs=250 ohm and the value of voltage is not allowed to fall below 8V what is the value of the load resistance (assume zero zener resistance)?
a) 16.87 ohm
b) 57.14 ohm
c) 89.12 ohm
d) 51.59 ohm
14. Which of the following technology is used for super buffers?
a) n-MOS technology
b) C-MOS technology
c) Bi-CMOS technology
d) ECL technology
15. What is the octal equivalent of the given binary number? (11011001010)
a) 3216
b) 3312
c) 3256
d) 6523
16. What will be the value of the following binary number if arithmetic left shift is performed? 101100011
a) 01100010 with overflow
b) 011000110 with overflow
c) 011000111 without overflow
d) 110110001 with overflow
17. Consider the expression given below:
P=QR+A
How many AND and OR gates will be required the same?
a) 2 AND , 2 OR
b) 2 AND
c) 1 AND , 2 OR
d) 2 OR
18. How many NAND gates are required to implement a XNOR gate in addition to one OR gate?
a) 1
b) 0
c) 3
d) 2
19. Which one of the given options is the correct of the below given binary addition?
10100101+00110110=?
a) 10111011
b) 11010111
c) 10011011
d) 11011011
20. What is the concentration Ni of a silicon semiconductor with a hole concentration 5000 cm-3 and doped with a concentration ND of 10^15 cm-3?
Ni=concentration of pure silicon
ND= concentration after doping with impurities
a) 10^11 cm-3
b) 10^20 cm-3
c) 2.23 x 10^9 cm-3
d) 10^14 cm-3
21. Consider the figure given below:
X=101101, Y=101011 Initially JK flip flop is reset. Find the output.
a) 010101
b) 000011
c) 011011
d) 010010
22. What is the simplified expression for F(X,Y,Z)= ℿ(0,2,4,5)?
a) X'Y'+X'Z'
b) XY+X'Z
c) X'Y+XZ'
d) X'Y'+X'Z
23. A synchronous counter is made of D FF and has outputs Q0Q1(MSB). It counts in the order 3,7,4,0,2,5,1,6. If D0D1D2(MSB) are the inputs to 3-bit synchronous counter to count the given sequence what is the input given to D1 FF.
a) Q2'Q0'+Q2'Q1+Q2Q1'Q0'
b) Q2'Q1'+Q2'Q0+Q2Q1
c) Q2Q1'+Q2'Q0'+Q2Q1Q0'
d) Q2'Q1'+Q2'Q0+Q2Q1Q0'
24. MVI A, # 4CH
RRC A,4
RLC
What is the content of A?
a) 44H
b) 4CH
c) C4H
d) 88H
25. What is the function implemented by the TTL Circuit shown?
a) OR gate
b) AND gate
c) XOR gate
d) XNOR gate
26. A PN junction has a diffusion capacitance of 9nF. If the junction is biased at 1 V and Vt threshold=0.0259 V with equal minority carrier lifetime in both the region and It is 1.2 microsecond , then what is the DC bias current?
a) 1 mA
b) 0.3885 mA
c) 0.2779 mA
d) 0.5923 mA
27. A colpitt's oscillator is oscillating at 325Hz. If L= 1mH C1= 1 uF what is the value of C2?
a) 0.315 uF
b) 0.315 F
c) 1 uF
d) 1 F
28. How many bits of information are stored by the circuit shown?
a) 4
b) 2
c) 1
d) No storage capacity
29. CMOS transistor are connected in the circuit shown below. The equivalent output Y equation for inputs A,B and C is
a) Y=[A.(B+C)]'
b) Y= [A+(B+C)]'
c) Y= [A+B+C]'
d) Y=[(AB)+C]'
30. How many FFs are required to build a binary counter circuit to count from 0 to 1023?
a) 1
b) 6
c) 10
d) 24
31. A BCD to XS-2 code converter has input B0B1B2B3 and output A0A1A2A3. Find the output A2.
a) B2'B3+B1'B3
b) B2'B1+B1'B2
c) B3'B1'+B1B2
d) B2'B1+B1B3
32. The decimal equivalent of the (D34EA)16 is
a) 30
b) 148226
c) 2250
d) 13848226
33. For the circuit J1=1011011 J2 = 0111010 , J3 = 11110000. K1=0001110, K2=1101100 , K3= 1010101 and Q=0011000. Find A1 and A2.
a) A1=AND A2=OR
b) A1=OR A2=OR
c) A1=AND A2=AND
d) A1=OR A2=AND
34. If is required to light 1024 light calculate total number of NAND gates required if each NAND has 4 fanouts
a) 413
b) 257
c) 195
d) 341
35. At 300k the Intrinsic carrier concentration of silicon is 1.5*10^16m-3. If the electron and hole mobilities are 0.13 and 0.05 m2/vs respectively, determine the intrinsic resistivity of silicon at 300K.
a) 0.243x10^4 ohm meter
b) 1.313x10^2 ohm meter
c) 2.315x10^3 ohm meter
d) 3.512x10^4 ohm meter
36. For 8085 microprocessor two bits A7-A0 and B7-B0 are added. When there is carry from addition of A4 and 64 which of the following flags will be set in PSW ?
a) Auxiliary carry
b) Carry flag
c) Overflow flag
d) None of the above
b) 131 usec
c) 49.8 usec
d) 1872 psec
2. For a JK Flip Flop the input J1=J1J2J3, where J1 =1011011, J2=0111010, J3=1111000 and K-KIK2K3, where K1=0001110, K2=1101100 K3=1010101. Initially Q=0 and there is one clock pulse for each bit time. Find the output Q?
a) 0110110
b) 0011000
c) 0010110
d) 0110010
3. Consider a Hartleys Oscillator where L1 = 1mH and L2=2mH, C=10uF. What is the frequency of oscillation? Now if C is increased 4 times, whereas L1 and L2 are changed by a factor of 8 and 1/2 respectively, what will be the new frequency of oscillation?
a) 112.31 Hz , fnew= 104.6 Hz
b) 103.1 Hz , fnew=99.7 Hz
c) 918.88 Hz , fnew=530.5 Hz
d) 126.67 Hz, fnew=125.2 Hz
4. The resistivity of an n-type silicon sample is 10 Ohm-cm. What is the donor impurity concentration if the mobility is 1000 cm2/V-s. Assume T = 300K.
a) 100 x 10^12 cm-3
b) 6.25 x 10^19 cm-3
c) 6.25 x 10^14 cm -3
d) 9.9875 x 10^14 cm³ -3
5. The reference voltage of a 6 bit R-2R ladder digital to analog converter is 7 V. Calculate the value of analog output voltage for an input of 010101.
a) 2.296875 V
b) 3.976595 V
c) 1.470235 V
d) 4.592685 V
6. If the current state (Q0Q1Q2Q3) of the following counter is 1000 then find out the output (Q0Q1Q2Q3) after 90 clock pulses.
b) 1100
c) 1000
d) 1111
7. Following set of instructions are executed on an 8085 Microprocessor. What is the final content of the accumulator? (carry is reset)
MVI A, A9H
RRC
MOV B, A
RRC,
ADD B
a) FE H with C=0
b) FF H with C=1
c) FF H with C=0
d) FE H with C=1
8. Calculate the value of Vout. (VBE of Q transistor =1.2 V)
b) 1.2
c) -1.2
d) -1.5
9. What is the output of the following program?
Module abc(x,y,z);
Output z;
Input x,y;
Assign y=(X'+XY');
Endmodule
a) X+Y'
b) X'+Y'
c) X+Y
d) X'+Y
10. The delay of the 1, 2 3, 4 gates are 7, 11, 13, 19 microseconds respectively. For certain values of x and z, together with certain transition of y, a glitch is generated for a short time, after which the output assumes Its correct value. Calculate the duration of the glitch. (Assume the wire delays are negligible).
b) 5 microseconds
c) 7 microseconds
d) 24 microseconds
11. If B= 11011 ,A <= B SRL-2 what is the content of A after the shift operation?
a) 00110
b) 01111
c) 01100
d) 11110
12. Calculate the resistivity of intrinsic silicon if the value of intrinsic carrier concentration (ni)=1.3x10^16/m3,electron mobility (un)=0.124 m^2/V-s hole mobility (up)=0.032m^2/V-s.
a) 3.086 x 10^3 Ωm
b) 7.112 x 10^3 Ωm
c) 5.786 x 10^3 Ωm
d) 9.453 x 10^3 Ωm
13. A 8V zener diode has knee current of 20mA and is supplied with a voltage of 12V. If Rs=250 ohm and the value of voltage is not allowed to fall below 8V what is the value of the load resistance (assume zero zener resistance)?
b) 57.14 ohm
c) 89.12 ohm
d) 51.59 ohm
14. Which of the following technology is used for super buffers?
a) n-MOS technology
b) C-MOS technology
c) Bi-CMOS technology
d) ECL technology
15. What is the octal equivalent of the given binary number? (11011001010)
a) 3216
b) 3312
c) 3256
d) 6523
16. What will be the value of the following binary number if arithmetic left shift is performed? 101100011
a) 01100010 with overflow
b) 011000110 with overflow
c) 011000111 without overflow
d) 110110001 with overflow
17. Consider the expression given below:
P=QR+A
How many AND and OR gates will be required the same?
a) 2 AND , 2 OR
b) 2 AND
c) 1 AND , 2 OR
d) 2 OR
18. How many NAND gates are required to implement a XNOR gate in addition to one OR gate?
a) 1
b) 0
c) 3
d) 2
19. Which one of the given options is the correct of the below given binary addition?
10100101+00110110=?
a) 10111011
b) 11010111
c) 10011011
d) 11011011
20. What is the concentration Ni of a silicon semiconductor with a hole concentration 5000 cm-3 and doped with a concentration ND of 10^15 cm-3?
Ni=concentration of pure silicon
ND= concentration after doping with impurities
a) 10^11 cm-3
b) 10^20 cm-3
c) 2.23 x 10^9 cm-3
d) 10^14 cm-3
21. Consider the figure given below:
a) 010101
b) 000011
c) 011011
d) 010010
22. What is the simplified expression for F(X,Y,Z)= ℿ(0,2,4,5)?
a) X'Y'+X'Z'
b) XY+X'Z
c) X'Y+XZ'
d) X'Y'+X'Z
23. A synchronous counter is made of D FF and has outputs Q0Q1(MSB). It counts in the order 3,7,4,0,2,5,1,6. If D0D1D2(MSB) are the inputs to 3-bit synchronous counter to count the given sequence what is the input given to D1 FF.
a) Q2'Q0'+Q2'Q1+Q2Q1'Q0'
b) Q2'Q1'+Q2'Q0+Q2Q1
c) Q2Q1'+Q2'Q0'+Q2Q1Q0'
d) Q2'Q1'+Q2'Q0+Q2Q1Q0'
24. MVI A, # 4CH
RRC A,4
RLC
What is the content of A?
a) 44H
b) 4CH
c) C4H
d) 88H
25. What is the function implemented by the TTL Circuit shown?
b) AND gate
c) XOR gate
d) XNOR gate
26. A PN junction has a diffusion capacitance of 9nF. If the junction is biased at 1 V and Vt threshold=0.0259 V with equal minority carrier lifetime in both the region and It is 1.2 microsecond , then what is the DC bias current?
a) 1 mA
b) 0.3885 mA
c) 0.2779 mA
d) 0.5923 mA
27. A colpitt's oscillator is oscillating at 325Hz. If L= 1mH C1= 1 uF what is the value of C2?
b) 0.315 F
c) 1 uF
d) 1 F
28. How many bits of information are stored by the circuit shown?
b) 2
c) 1
d) No storage capacity
29. CMOS transistor are connected in the circuit shown below. The equivalent output Y equation for inputs A,B and C is
b) Y= [A+(B+C)]'
c) Y= [A+B+C]'
d) Y=[(AB)+C]'
30. How many FFs are required to build a binary counter circuit to count from 0 to 1023?
a) 1
b) 6
c) 10
d) 24
31. A BCD to XS-2 code converter has input B0B1B2B3 and output A0A1A2A3. Find the output A2.
a) B2'B3+B1'B3
b) B2'B1+B1'B2
c) B3'B1'+B1B2
d) B2'B1+B1B3
32. The decimal equivalent of the (D34EA)16 is
a) 30
b) 148226
c) 2250
d) 13848226
33. For the circuit J1=1011011 J2 = 0111010 , J3 = 11110000. K1=0001110, K2=1101100 , K3= 1010101 and Q=0011000. Find A1 and A2.
b) A1=OR A2=OR
c) A1=AND A2=AND
d) A1=OR A2=AND
34. If is required to light 1024 light calculate total number of NAND gates required if each NAND has 4 fanouts
a) 413
b) 257
c) 195
d) 341
35. At 300k the Intrinsic carrier concentration of silicon is 1.5*10^16m-3. If the electron and hole mobilities are 0.13 and 0.05 m2/vs respectively, determine the intrinsic resistivity of silicon at 300K.
a) 0.243x10^4 ohm meter
b) 1.313x10^2 ohm meter
c) 2.315x10^3 ohm meter
d) 3.512x10^4 ohm meter
36. For 8085 microprocessor two bits A7-A0 and B7-B0 are added. When there is carry from addition of A4 and 64 which of the following flags will be set in PSW ?
a) Auxiliary carry
b) Carry flag
c) Overflow flag
d) None of the above
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