Monday, June 23, 2014

IES 2009 E & T Solved Question paper 2 Objective

1. Consider the following:
     1. Oscillator
     2. Emitter follower
     3. Cascaded amplifier
     4. Power amplifier
Which of these use feedback amplifiers?
a) 1 and 2
b) 1 and 3
c) 2 and 4
d) 3 and 4

Ans: Option a)

2. Why npn-transistors are preferred over pnp transistors?
a) Leakage current in NPN-transistors is less than pnp-transistors.
b) Mobility of majority carrier in npn-transistors is greater than the mobility of majority carriers in pnp-transistors.
c) Bias voltage required in npn is less than in pnp-transistors.
d) Bias voltage required in npn is greater than in pnp-transistors.

Ans: Option b)

3. Consider the following statements
To draw a.c. equivalent circuit of a transistor all
1.     d.c. sources are shorted
2.     a.c. sources are shorted
3.     d.c. sources are opened
4.     a.c. sources are connected to d.c. sources
Which of the above statements is/are correct?
a)     2 and 4
b)     1 and 2
c)     1 only
d)     3 and 4

Ans: Option c)

4.     Which one of the following statements is not correct with regard to power amplifiers?
a)     The collector current is large
b)     They are used as the front end of multistage amplifier
c)     They are used near the end of multistage amplifier
d)     They have a high power rating (>1/2 W)

Ans: Option b)

5.     Consider the following statements regarding the Class-B power amplifiers(Complementary symmetry type):
1.     The efficiency of the amplifier is higher than that of Class-A amplifier
2.     The power output is low
3.     Cross-over distortion is present
4.     The standby power dissipation is absent
Which of the above statements are correct?

a)     1,2 and 3
b)     1,2 and 4
c)     1, 3 and 4
d)     2, 3 and 4

Ans: Option c)

6. Consider the following:
1. Distortion
2. Gain
3. Bias Stabilization
4. Sensitivity
5. Frequency Response

Which of these properties of the power amplifier one should concentrate upon while designing a good power amplifier circuit?
a)     1, 2 and 3
b)     1, 3 and 5
c)     2, 3 and 4
d)     4 and 5

Ans: Option a)

7. Consider the following:
1. Coupling Capacitor
2. Emitter by-pass capacitor
3. Emitter to base diffusion capacitance of the BJT
4. Stray capacitance of the circuit.
Which of these components in a R-C coupled amplifier control the lower cut-off frequency of the amplifier?
a)     1 and 2
b)     2 and 3
c)     3 and 4
d)     1 and 4
Ans: Option a)

8. Which one of the following is a regulated power supply?
a) IC 555
b) IC 844
c) IC 3080
d) IC 723

Ans: Option d)

9. Consider the following statements regarding an OP-AMP:
1. All types of negative feedback reduce non-linear distortion
2. All types of negative feedback reduce the output offset voltage
3. Non-inverting (current and voltage) feedback increases the input impedance
4. Inverting (current and voltage) feedback decreases the input impedance
Which of the above statements is/are correct?
a)     1 only
b)     2 and 3 only
c)     2 and 4 only
d)     1, 2, 3 and 4

Ans: Option d)

10. Consider the following statements:
The bias stability of an emitter-bias amplifier circuit improves by
1.     Decreasing the value of RB.
2.     Increasing the value of RE.
3.     Decreasing the value of RE.
4.     Increasing the value of RB.
5.     Increasing the value of RC.
Which of the above statements are correct?
a)     1 and 2
b)     2 and 3
c)     3 and 4
d)     4 and 5
Ans: Option a)

11. Which of the following will be true for a CE transistor amplifier if the emitter resistor value is made equal to zero?
1. Its gain will increase.
2. Its stability will increase.
3. Its gain will decrease.
4. Its stability will decrease.
Select the correct answer from the codes given below:
a)     1 and 2
b)     2 and 3
c)     3 and 4
d)     1 and 4

Ans: Option d)

12. Which one of the following circuits is used for converting a sine wave into square wave?
a) Astable multivibrator
b) Monostable Multivibrator
c) Bistable Multivibrator
d) Schmitt Trigger
Ans: Option d)

13. Which of the transistor models is most preferred for the analysis of a transistor circuit both at mid-band and at high frequencies?
a) h-parameter model
b) y-parameter model
c) s-parameter model
d) hybrid-π model
Ans: Option d)

14. Which of the following describe the correct properties of an emitter follower circuit?
1. It is a voltage series feedback circuit.
2. It is a current series feedback circuit.
3. Its voltage gain is less than unity.
4. Its output impedance is very low.
Select the correct answer from the codes given below:
a)     1, 3 and 4
b)     2, 3 and 4
c)     2 and 3 only
d)     2 and 4 only

Ans: Option a)

15. Which one of the following type of negative feedback increases the input resistance and decreases the output resistance of an amplifier?
a) Current series feedback
b) Voltage series feedback
c) Current shunt feedback
d) Voltage shunt feedback

Ans: Option b)


16.Which one of the following oscillators is well suited for the generation of wide range audio frequency sine waves?
a) RC phase-shift oscillator
b) Wien-bridge oscillator
c) Col-pitts oscillator
d) Hartley oscillator
Ans: Option b)

17. Consider the following statements regarding a good power supply:
1. The a.c. ripple should be high
2. Sv, (Voltage stability factor) should be low
3. ST, (Temperature stability factor) should be low.
Which of the above statements are correct?
a)     1, 2 and 3
b)     2 only
c)     3 only
d)     2 and 3 only
Ans: Option d)

18. Which of the following are the non-linear applications of OP-AMP?
1. Current-to-voltage convertor
2. Comparator
3. Peak detector
4. Limiter
Select the correct answer from the codes given below:
a)     1, 2 and 3
b)     2, 3 and 4
c)     1, 3 and 4
d)     1, 2 and 4
Ans: Option b)

19. Consider a 565 PLL with RT = 10 KΩ and CT = 0.01 μF. What is the output frequency of the VCO?
a) 10 kHz
b) 5 kHz
c) 2.5 kHz
d) 1.25 kHz
Ans: Option c)

20. Which of the following does not show non-linear V-I characteristics?
a) Schottky diode
b) Tunnel diode
c) Thermistor, at a fixed temperature
d) p-n junction diode
Ans: Option c)

21. Which of the following conditions must be satisfied for a transistor to remain under saturation?
1. Its collector to base junction should be under forward bias.
2. Its collector to base junction should be under reverse bias.
3. Its emitter to base junction should be under reverse bias.
4. Its emitter to base junction should be under forward bias.
Select the correct answer from the codes given below:
a)     1 and 2
b)     1 and 3
c)     2 and 3
d)     1 and 4
Ans: Option d)
22. Which junction has least junction capacitance?
a) Alloy
b) Grown
c) Diffused
d) Point contact
Ans: Option d)

23. Assertion (A): A fixed bias BJT circuit exhibits better performance as compared to a self bias BJT circuit.
Reason (R) : A fixed bias BJT circuit uses less components as compared to self bias BJT circuit.
a)     Both A and R are individually true and R is the correct explanation of A
b)     Both A and R are individually true but R is not the correct explanation of A
c)     A is true but R is false
d)     A is false but R is true

Ans: Option d)

24. Assertion (A): The small signal analysis of a transistor amplifier is done to obtain the current gain, voltage gain and the conversion efficiency of an amplifier.
Reason (R): The small signal analysis of a transistor amplifier uses the small signal parameter of the transistor.
a)     Both A and R are individually true and R is the correct explanation of A
b)     Both A and R are individually true but R is not the correct explanation of A
c)     A is true but R is false
d)     A is false but R is true

Ans: Option d)

25. Assertion (A): A rectifier with inductor filter is more efficient for high load current.
Reason(R): In rectifier with inductor filter we can use a larger choke to reduce ripple, larger choke will have higher dc resistance which will result in lower dc output voltage for higher load current.
a)     Both A and R are individually true and R is the correct explanation of A
b)     Both A and R are individually true but R is not the correct explanation of A
c)     A is true but R is false
d)     A is false but R is true

Ans: Option a)

26. Assertion (A): It is not desirable to drive a transistor into hard saturation in high speed switching circuits.
Reason (R): It may not be possible to bring it back to cut off state, if it is driven into hard saturation
a)     Both A and R are individually true and R is the correct explanation of A
b)     Both A and R are individually true but R is not the correct explanation of A
c)     A is true but R is false
d)     A is false but R is true

Ans: Option c)


27. What are the ultimate purposes of minimizing logic expressions?
1. To get a small size expression.
2. To reduce the number of variables in the given expression.
3. To implement the function of the logic expression with least hardware.
4. To reduce the expression for making it feasible for hardware implementation.
Select the correct answer from the codes given below:
a.      1 only
b.     2 and 3
c.      3 only
d.     3 and 4

Ans: Option d)

28. Which of the following factors are responsible to design IC logic gates to operate at a fixed supply voltage of 5 volts?
1. Low heating of IC logic gates.
2. Compatibility with other logic gates.
3. Satisfactory and safe operation.
4. Standardization from IC Manufacturing point of view.
Select the correct answer from the below codes:
a)     1 only
b)     2 only
c)     2 and 3
d)     3 and 4

Ans: Option c)

29. Which of the following statements is not correct?
a) Propagation delay is the time required for a gate to change its state.
b) Noise immunity is the amount of noise which can be applied to the input of a gate without causing the gate to change state
c) Fan-in of a gate is always equal to fan-out of the same gate
d) Operating speed is the maximum frequency at which digital data can be applied to a gate

Ans: Option c)

30. Which of the following are universal gates?
1. NAND
2. NOR
3. XOR
Select the correct answer from the codes given below:
a)     1 and 2 only
b)     1 and 3 only
c)     2 and 3 only
d)     1,2 and 3

Ans: Option a)

31. Which of the following output configurations are available in a TTL gate?
1. Open collector output
2. Totem-pole output
3. Tristate output
Select the correct answer from the codes given below
a)     1 only
b)     1 and 2 only
c)     2 and 3 only
d)     1,2 and 3

Ans: Option d)

32. Which one of the following logic families can be operated using a supply voltage from 3V to 15V?
a) TTL
b) ECL
c) PMOS
d) CMOS

Ans: Option d)

33. Which of the following circuits come under the class of combinational logic circuits?
1. Full adder
2. Full subtractor
3. Half adder
4. J-K Flip-flop
5. Counter
Select the correct answer from the codes given below:
a)     1 only
b)     3 and 4
c)     4 and 5
d)     1, 2 and 3

Ans: Option d)

34. Consider a multiplexer with X and Y as data inputs and Z as control input. Z = 0 selects input X and Z = 1 selects input Y. What are the connections required to realize the 2-variable Boolean function f = T + R, without using any additional hardware?
a) R to X, 1 to Y, T to Z
b) T to X, R to Y, T to Z
c) T to X, R to Y, 0 to Z
d) R to X, 0 to Y, T to Z
Ans: Option a)

35. With which decoder it is possible to obtain many code conversions?
a) 2 line to 4 line
b) 3 line to 8 line
c) not possible with any decoder
d) 4 line to 16 line decoder

Ans: Option d)

36. Match List-I (Application of Circuits) with List-II (Circuit name) and select the correct answer using the correct code given below the lists:
List-I
A.   Divider
B.    Clips input voltage at two pre-determined levels
C.    Square wave generator
D.   Narrow current pulse generator
List-II
1.     Astable multivibrator
2.     Schmitt trigger
3.     Bistable Multivibrator
4.     Blocking Oscillator
Codes:
     A  B       C       D
a)  4   2        1        3
b) 3    2        1        4       
c) 4    1        2        3
d) 3    1        2        4

Ans: Option d)


37. Consider the following statements:
For a master-slave J-K Flip-flop,
1.     The toggle frequency is the maximum clock frequency at which the flip-flop will toggle reliably.
2.     The data input must precede the clock triggering edge transition time by some minimum time.
3.     The data input must remain fixed for a given time after the clock triggering edge transition time for reliable operation.
4.     Propagation delay time is equal to the rise time and fall time of the data.
Which of the above statements is/are correct?
a)     1, 2 and 3
b)     1 and 2 only
c)     2 and 3 only
d)     3 and 4 only


Ans: Option a)

38. Consider the following statements:
1. A flip-flop is used to store 1-bit of information.
2. Race-around condition occurs in a J-K flip-flop when both the inputs are 1.
3. Master-slave configuration is used in flip-flops to store 2-bits of information.
4. A transparent latch consists of a D-type flip-flop

Which of the above statements is/are correct?
a)     1 only
b)     1, 3 and 4
c)     1, 2 and 4
d)     2 and 3 only

Ans: Option c)

39. Which of the following flip-flops is used as a latch?
a)J-K flip-flop
b) R S flip-flop
c) T flip-flop
d) D flip-flop

Ans: Option d)

40. Which of the following conditions should be satisfied to call an astable multivibrator circuit using discrete components as a digital circuit?
1. A flip-flop is always a digital circuit.
2. Only when we assign 1 and 0 to the high and low a level of the output, a flip-flop is called a digital circuit.
3. Only if the power supply voltage is maintained at +5V or -5V, it is called a digital circuit
4. Only if it is in IC form, following the technology of IC Manufacture, it is called a digital circuit.
Select the correct answer from the codes given below:
a)     1 only
b)     2 and 3
c)     2 only
d)     3 and 4

Ans: Option a)


41. Which of the following Boolean algebra rules is correct?
a) A.A’ = 1
b) A + AB = A+ B
c) A + A’B = A+ B
d) A(A+B) = B


Ans: Option c)

42. Which of the following comes under the class of sequential logic circuits?

1. Full adder
2. Full subtractor
3. Half adder
4. J-K Flip-flop
5. Counter
Select the correct answer from the codes given below:
a)     1 and 2
b)     2 and 3
c)     3 and 4
d)     4 and 5


Ans: Option d)

43. Consider the following statements regarding registers and latches:
1. Registers are made of edge triggered FFs whereas latches are made from level-triggered FFs.
2. Registers are temporary storage devices whereas latches are not
3. A latch employs cross-coupled feedback connections.
4. A register stores a binary word whereas a latch does not.
Which of the above statements is/are correct?
a)     1 only
b)     1 and 3
c)     2 and 3
d)     3 and 4


Ans: Option b)


44. Which of the following abilities are available in a universal Shift register?
1. Shift Left
2. Shift Right
3. Parallel Load
4. Serial add
Select the correct answer from the codes given below:
a)     2 and 4 only
b)     1, 2 and 3
c)     1, 2 and 4
d)     1, 3 and 4

Ans: Option b)


45. Which of the following measurements can be done using a counter?
1. Pulse duration
2. Interval between two pulses
3. Amplitude of the pulse
4. Rise time of a pulse
Select the correct answer from the codes given below:
a)     1 and 2
b)     2 and 3
c)     1 and 4
d)     2 and 4

Ans: Option a)

46. Match List-I (Type of N-bit ADC) with List-II (Characteristics) and select the correct answer using the codes given below the lists:
List-I
A.   Flash Converter
B.    Successive Approximation
C.    Counter Ramp
D.   Dual Slope
List-II
1.     Integrating Type
2.     Fastest converter
3.     Maximum conversion time = N bits
4.     Uses a DAC in its feedback path
Codes:
a)     2        3        4        1
b)     1        3        4        2
c)     2        4        3        1
d)     1        4        3        2

Ans: Option a)

47. In which one of the following types of analog to digital converters the conversion time is practically independent of the amplitude of the analog signal?
a) The dual slope integrating type
b) Successive Approximation Type
c) Counter ramp type
d) Tracking type

Ans: Option b)

48. Assertion (A): When all inputs of a NAND gate are shorted to get a one input, one output gate, it becomes an inverter.
Reason (R): When all inputs of a NAND-gate are at logic ‘0’ level, the output is at logic ‘1’.
a)     Both A and R are individually true and R is the correct explanation of A
b)     Both A and R are individually true but R is not the correct explanation of A
c)     A is true but R is false
d)     A is false but R is true


Ans: Option b)

49. Which of the following statements about the matched filter in a communication receiver are correct?
1. Its impulse response depends on the signal shape.
2. It maximizes the SNR at the detection stage.
3. It produces ISI.
4. It may produce phase error if synchronization is improper.
Select the correct answer from the codes given below:
a)     1 and 4 only
b)     1 and 2 only
c)     2, 3 and 4
d)     1,2 and 4

Ans: Option b)

50. A single mode fibre does not suffer from which type of dispersion?
a) Waveguide dispersion
b) Material dispersion
c) Intermodal dispersion
d) Polarization mode dispersion

Ans: Option c)

51. A balanced modulator is used in the generation of which of the following?
a) DSB-SC signal
b) FM signal
c) PM signal
d) PAM signal

Ans: Option a)

52. An amplitude modulated signal occupies a frequency range from 395 kHz to 405 kHz. It can be demodulated by which of the following?
a) Using an envelope detector and filter
b) Multiplying with a 395 kHz local signal
c) Multiplying with a 405 kHz local signal
d) Low pass filtering with cut off at 400 kHz

Ans: Option d)

53. An audio signal is band limited to 4 kHz. It is sampled at 8 kHz. What will be the spectrum of the sampled signal?
a) -4 kHz to 4 kHz
b) -8 kHz to 8 kHz
c) every 4n kHz and repeating
d) every +- 8 kHz and repeating as well as at zero (k integer)

Ans: Option d) 


54. A signal occupies a band 5 kHz to 10 kHz. For proper error free reconstruction at what rate it should be sampled?
a) 10 kHz
b) 20 kHz
c) 5 kHz
d) (10 + 5)  x 2 kHz

Ans: Option a)

55. The spectral range of a band pass signal extends from 10 MHz to 10.4 MHz. What is the minimum sampling frequency required for reconstruction?
a) 20 MHz
b) 20.8 MHz
c) 20.4 MHz
d) 0.8 MHz


Ans: Option d)


56. An audio signal is to be transmitted digitally. Which is the system best suited for good fidelity?
a) 8 bit PCM
b) 13 bit PCM
c) 32 bit PCM
d) PCM system with non-uniform quantizer

Ans: Option d)

57. For good quality signal transmission all frequency components should have the same transmission delay, td and same phase shift -ᵠ s. What can be said about the statement?
a) correct
b) True for td but not for ᵠ s
c) Not true for td but true for ᵠ s
d) Both td and ᵠ s are not involved in the equality
Ans: Option b)

58. Which of the following introduces mode partition noise?
a) coaxial line
b) Waveguide
c) Fibre transmission line
d) Both coaxial line ans waveguide


Ans: Option c)


59. Which of the following doesn’t cause losses in optical fibre cables?
a) Impurities
b) Microbending
c) Attenuation in glass
d) Stepped index operation

Ans: Option d)

60. On which bands, do the optical fibres operate?
1. Ultra violet band
2. Ultra high frequency band
3. Visible light band
4. Infra red band
Select the correct answer from the codes given below:
a)     1 only
b)     1 and 2 only
c)     1, 2 and 3
d)     1, 3 and 4


Ans: Option d)


61. Which one of the following photo-detector doesn’t provide gain?
a) Photo-transistor
b) Photo conductor
c) Avalanche photodiode
d) p-i-n photodiode

Ans: Option d)

62. Consider the following statements:
In case of space wave propagation, the signal strength at the receiver is
1.     Directly proportional to transmitter and receiver heights
2.     Inversely proportional to distance between transmitter and receiver
3.     Directly proportional to the frequency.
Which of the above statements is/are correct?
a)     1 and 2
b)     1 and 3
c)     2 and 3
d)     3 only

Ans: Option b)

63. What was the first commercial geostationary communication satellite?
a) INTELSAT 1
b) ECHO
c) INSAT-1A
d) SPUTNIK

Ans: Option a)

64. What does a link budget for satellite communication include?
a) Total cost of the satellite
b) Cost of satellite plus launch vehicle
c) Signal and noise levels in dB
d) Margins of error permitted

Ans: Option c)

65. Which one of the following statements is correct?
a) AGC in radio receivers will keep the total signal output fairly constant but the noise component will be reduced, with the result S/N ratio will improve
b) AGC in radio receivers is a linear operation w.r.t both signals and noise
c) Sudden changes in the output while tuning which may cause damage to the components, is an unavoidable feature of AGC
d) AGC operation is independent of filter components used in the AGC circuit.


Ans: Option c)


66. Consider the following statements:
1. Taking 2’s complement representation is equivalent to sign change.
2. In the 2’s complement representation the most significant bit (MSB) is zero for a positive number.
3. In a 4 bit binary representation of a binary number A, A + 1’s complement of A = 24.
Which of the above statements are correct?
a)     1 and 2 only
b)     1 and 3 only
c)     2 and 3 only
d)     1, 2 and 3

Ans: Option a)

67. Consider the following statements:
1. Strictly speaking C supports 1 dimensional array only.
2. An array element may be an array by itself.
3. Array elements need not occupy contiguous memory locations.
Which of the above statements is/are correct?
a)     1 only
b)     2 only
c)     1 and 2
d)     2 and 3

Ans: Option b)

68. What can be the maximum dimension of an array in C language program>
a) 3
b) 4
c) 5
d) It is compiler dependent

Ans: Option d)

69. With reference to C programming language, which of the following statements are correct?
1. An identifier may start with an underscore.
2. An identifier may end with an underscore.
3. IF is a valid identifier.
4. The number of significant characters in an identifier is implementation dependent.
Select the correct answer from the codes given below:
a)     1 and 2 only
b)     2 and 3 only
c)     1, 2, 3 and 4
d)     3 and 4 only

Ans: Option c)
70. How many distinct binary trees can be constructed with three nides?
a) 1
b) 2
c) 3
d) 5

Ans: Option d)

71. Consider the following statements:
1. Internal sorting is used if the number of items to be sorted is very large.
2. External sorting is used if the number of items to be sorted is very large.
3. External sorting needs auxiliary storage.
4. Internal sorting needs auxiliary storage.
Which of the above statements are correct?
a)     1 and 2
b)     2 and 3
c)     3 and 4
d)     2 and 4

Ans: Option b)

72. Which of the following has a major role in implementation of function calls in C?
a) Processor’s register
b) Data segment
c) The heap
d) System stack

Ans: Option d)

73. Which one of the following algorithms design techniques is used in quick sort algorithms?
a) Dynamic programming
b) Back tracking
c) Divide and conquer
d) Greedy

Ans: Option c)

74. There are four different algorithms A1, A2, A3 and A4 to solve a given problem with the complexity order log (n), log (log (n)), n log(n) and n/log(n) respectively.
Which is the best algorithm?
a)     A1
b)     A2
c)     A3
d)     A4

Ans: Option b)


75. Which of the following is/are correct statement (s)?
1. Bus is a group of wires carrying information.
2. Bus is needed to achieve reasonable speed of operation.
3. Bus can carry data or address.
4. A bus can be shared by more than one device.
Select the correct answer from the codes given below:
a)     1 only
b)     1 and 2 only
c)     2, 3 and 4 only
d)     1, 2, 3 and 4
Ans: Option d)

76. Which of the following is included in the architecture of a computer?
1. Addressing modes, CPU
2. Instruction set, data formats
3. Secondary memory, Operating system
Select the correct answer from the codes given below:
a)     1 and 2
b)     1 and 3
c)     2 and 3
d)     3 only

Ans: Option a)

77. A 3 x 8 decoder with two enable inputs is to be used to address 8 blocks of memory. What will be the size of each memory block when addressed from a sixteen bit bus with two MSBs used to enable the decoder?
a) 2 K
b) 4 K
c) 16 K
d) 64 K


Ans: Option a)


78. Match List-I (Type of Memory) with List-II (Used as) and select the correct answer using the code given below the lists:
List-I
A.   DRAM
B.    SRAM
C.    Parallel Access Registers
D.   ROM
List-II
1.     Cache Memory
2.     Main Memory
3.     BIOS Memory
4.     CPU registers

Code:
          A       B       C       D
a)     1        4        2        3
b)     3        4        2        1
c)     1        2        4        3
d)     3        2        4        1

Ans: Option c)

79. Which of the following are the memory performance parameters?
1. Access time and latency
2. Block size and Block access time
3. Cycle time and bandwidth
Select the correct answer from the codes given below:
a)     1 only
b)     1 and 2 only
c)     2 and 3 only
d)     1, 2 and 3

Ans: Option d)

80. What is the address space of 8086 CPU?
a) One Megabyte
b) 256 kilobyte
c) 1 K Megabytes
d) 64 kilobytes

Ans: Option a)
81. Which of the following counters can be used to divide the clock frequency of the microprocessor by 5?
a) 3 bit counter
b) 5 bit counter
c) mod 3 counter
d) mod 5 counter

Ans: Option d)

82. Identification of highest priority interrupt can be achieved in a minimum time by which of the following schemes?
a) Hardwired polling
b) Priority encoder circuit
c) Software polling
d) Subdivision of interrupt registers into a number of sub-registers which are checked parallel

Ans: Option a)

83. Which of the following is used as the interface chip for data transmission between 8086 and a 16-bit ADC?
a) 8259
b) 8255
c) 8253
d) 8251

Ans: Option b)

84. Which one of the following addressing modes is used in the instruction PUSH B?
a) Direct
b) Register
c) Register Indirect
d) Immediate

Ans: Option b)

85. What is the purpose of a start bit in RS232 serial communication protocol?
a) To synchronize receiver for receiving every byte.
b) To synchronize receiver for receiving a sequence of byte.
c) Acts as a parity bit
d) To synchronize receiver for receiving the last byte.
Ans: Option b)

86. The resolution of a DAC depends on which of the following?
a) The number of bits
b) Monotonocity
c) Reference
d) The values of resistance

Ans: Option a)


87. What is the purpose of DMA facility in microprocessor based system?
a) To increase the speed of data transfer between the μP and I/O devices.
b) To increase the speed of data transfer between the μP and memory.
c) To increase the speed of data transfer between the memory and the I/O devices.
d) To improve the reliability of the system.

Ans: Option c)

88. Personal Computer cannot be used for which one of the following?
a) Game Playing
b) Weather Forecasting
c) Office Automation
d) Home Computing

Ans: Option b)

89. What is the characteristic of a good control system?
a) Sensitive to parameter variation.
b) Insensitive to input command.
c) Neither sensitive to parameter variation nor sensitive to input commands.
d) Insensitive to parameter variation but sensitive to input commands.

Ans: Option d)

90. How can the bandwidth of a control system be increased?
a) By the use of phase lead network.
b) By the use of phase lag network.
c) By the use of both phase-lag and phase-lead network.
d) By the use of cascaded amplifiers in the system.

Ans: Option a)
91. Which of the following may result in instability problem?
a) Large error
b) High Selectivity
c) High Gain
d) Noise

Ans: Option c)

92.  A negative feedback closed-loop system is supplied to an input of 5V. The system has a forward gain of 1 and a feedback gain of 1. What is the output voltage?
a) 1.0 V
b) 1.5 V
c) 2.0 V
d) 2.5 V

Ans: Option d)

93. For what positive value of K does the polynomial
s4+ 8s3+ 24s2+32s+K
Have roots with zero real parts?
a)     10
b)     20
c)     40
d)     80

Ans: Option d)

94. How many roots with positive real parts do the equation s3 + s2 – s + 1 = 0 have?
a) Zero
b) One
c) Two
d) Three

Ans: Option c)

95.  The characteristics equation of a control system is given as
s4 + 8s3 + 24s2 + 32s + K = 0
What is the range of values of K for this system to be stable?
a)     0 <= K< 80
b)     0 <= K< 100
c)     0 <= K< 300
d)      0 <= K< 600

Ans: Option a)

96. Which of the following can be used as a tacho generator in control system?
a) Microsyn
b) DC servomotor
c) AC servomotor
d) Magnetic amplifier

Ans: Option c)

97. Consider the equation
s2 + 2s + k (s+2) = 0
Where do the roots of this equation break on the root loci plot?
a)     -3.414
b)     -2.414
c)     -1.414
d)     -.0.414

Ans: Option a)

98. How many number of branches does the root loci of the equation
s(s+2)(s+3)+K(s+1) = 0 have?
a)     Zero
b)     One
c)     Two
d)     Three

Ans: Option d)

99. The characteristic equation of a control system is given as
s4 + 4s3 + 4s2 + 3s + K = 0
What is the value of K for which this system is marginally stable?
a)     9/16
b)     19/16
c)     29/16
d)     39/16

Ans: Option d)

100. The transfer function of a controller is given as Kp + Kd.s where Kp and Kd are constant. What type of controller is this?
a) Proportional
b) Proportional plus integral
c) Proportional plus derivative
d) Integral plus derivative

Ans: Option c)

101. The transfer function of a linear-time-invariant system is given as 1/(s+1). What is the steady-state value of the unit-impulse response?
a) Zero
b) One
c) Two
d) Infinite

Ans: Option a)

102. Consider the function F(s) = w/ (s2 + w2) where F(s) is the Laplace transform of f(t). What is the steady state value of f(t)?
a) Zero
b) One
c) Two
d) A value between –1 and +1


Ans: Option d)

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