MCQOPTIONS
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MCQOPTIONS
This section includes 657 Mcqs, each offering curated multiple-choice questions to sharpen your Testing Subject knowledge and support exam preparation. Choose a topic below to get started.
| 1. |
Which of the following memories normally has highest storage capacity? |
| A. | Magnetic disc |
| B. | Magnetic tape |
| C. | Semiconductor memory |
| D. | Core memory |
| Answer» B. Magnetic tape | |
| 2. |
The number of comparators of needed in a parallel conversion type 8 bit A to D converter is |
| A. | 8 |
| B. | 16 |
| C. | 255 |
| D. | 256 |
| Answer» D. 256 | |
| 3. |
11012 - 10012 = |
| A. | 1000 |
| B. | 0100 |
| C. | 0010 |
| D. | 0001 |
| Answer» C. 0010 | |
| 4. |
A master slave flip-flop has the characteristics that |
| A. | change in the I/P immediately reflected in the O/P |
| B. | change in the O/P occurs when the state of the master is affected |
| C. | change in the output occurs when the state of the slave is affected |
| D. | both the master and the slave states are affected at the same time |
| Answer» D. both the master and the slave states are affected at the same time | |
| 5. |
Least expensive logic |
| A. | RTL |
| B. | DTL |
| C. | TTL |
| D. | ECL |
| Answer» B. DTL | |
| 6. |
Which of the following flip-flops is used as latch? |
| A. | JK flip-flop |
| B. | D flip-flop |
| C. | RS flip-flop |
| D. | T flip-flop |
| Answer» D. T flip-flop | |
| 7. |
The circuit show in the figure has 4 boxes each described by inputs P, Q, R and outputs y, z withY = P Q R, Z = RQ + PR + QP The circuit act as a |
| A. | 4 bit adder giving P + Q |
| B. | 4 bit subtractor P - Q |
| C. | 4 bit subtractor Q - P |
| D. | 4 bit adder P + Q + R |
| Answer» C. 4 bit subtractor Q - P | |
| 8. |
Periodic recharging of the memory cells at regular intervals of 3 to 8 millisecond is required in a |
| A. | ROM |
| B. | Static RAM |
| C. | Dynamic RAM |
| D. | PLA |
| Answer» D. PLA | |
| 9. |
In order to enable RST 5.5, RST 6.5 and RST 7.5 interrupts, which of the following instructions are needed? |
| A. | El only |
| B. | SIM only |
| C. | El and SIM only |
| D. | None |
| Answer» D. None | |
| 10. |
The frequency of the driving network connected between pins 1 and 2 of a 8085 chip must be |
| A. | equal to the desired clock frequency |
| B. | twice the desired clock frequency |
| C. | four times the desired clock frequency |
| D. | eight times the desired clock frequency |
| Answer» C. four times the desired clock frequency | |
| 11. |
Assertion (A): Divide-64 counter is a Mod-64 counter and divides the input frequency by 64 Reason (R): A Mod 64 counter can be obtained by cascading Mod 16 and Mod 4 counters. |
| A. | Both A and R are correct and R is correct explanation of A |
| B. | Both A and R are correct but R is not correct explanation of A |
| C. | A is true, R is false |
| D. | A is false, R is true |
| Answer» C. A is true, R is false | |
| 12. |
Digital technologies being used now-a-days are |
| A. | DTL and EMOS |
| B. | TTL, ECL, CMOS and RTL |
| C. | TTL, ECL and CMOS |
| D. | TTL, ECL. CMOS and DTL |
| Answer» C. TTL, ECL and CMOS | |
| 13. |
Schmitt trigger can be used as a |
| A. | comparator |
| B. | square-wave generator |
| C. | flip-flop |
| D. | all of these |
| Answer» E. | |
| 14. |
A seven bit code (even parity) 1111101 may have error. The correct code is |
| A. | 1111101 |
| B. | 1111111 |
| C. | 0101011 |
| D. | 1100011 |
| Answer» C. 0101011 | |
| 15. |
Most of the digital computers do not have floating-point hardware because |
| A. | floating point hardware is costly |
| B. | it is slower than software |
| C. | it is not possible to perform floating point addition by hardware |
| D. | of not specific reason |
| Answer» B. it is slower than software | |
| 16. |
Consider the following statements in connection with CMOS inverter in figure where both the MOSFET are of enhancement type and both have a threshold voltage of 2 Vstatements 1: T1 conducts when vi 2 Vstatements 2: T1 is always in saturation when v0 = 0 VWhich of the following is correct? |
| A. | Only statement 1 is true |
| B. | Only statement 2 is true |
| C. | Both the statement are true |
| D. | Both the statements are false |
| Answer» B. Only statement 2 is true | |
| 17. |
The number of FF required for a divide by 12 circuit is |
| A. | 16 |
| B. | 12 |
| C. | 8 |
| D. | 4 |
| Answer» E. | |
| 18. |
The energy to cause thermionic emission is supplied by heating the cathode. |
| A. | True |
| B. | False |
| Answer» B. False | |
| 19. |
Assertion (A): In an n-p-n transistor as the electrons enter the collector region, they are accelerated towards the collector terminal. Reason (R): Emitter base junction in BJT is forward biased. |
| A. | Both A and R are true and R is correct explanation of A |
| B. | Both A and R are true but R is not a correct explanation of A |
| C. | A is true but R is false |
| D. | A is false but R is true |
| Answer» C. A is true but R is false | |
| 20. |
Assertion (A): In reverse biased p-n junction, the reverse saturation current is nearly constant if the reverse voltage is less than critical value. Reason (R): The total reverse current is sum of reverse saturation current and surface leakage current. |
| A. | Both A and R are true and R is correct explanation of A |
| B. | Both A and R are true but R is not a correct explanation of A |
| C. | A is true but R is false |
| D. | A is false but R is true |
| Answer» C. A is true but R is false | |
| 21. |
If 10 V is the peak voltage across the secondary of the transformer in a half wave rectifier (without any filter circuit), then the maximum voltage on the reverse biased diode will be |
| A. | 20 V |
| B. | 14.14 V |
| C. | 10 V |
| D. | 7.8 V |
| Answer» D. 7.8 V | |
| 22. |
Given a power supply filter circuit, what measurements must be made of determine percentage regulation |
| A. | current through and voltage across the capacitor |
| B. | d.c. load voltage and r.m.s. load voltage |
| C. | current through load and voltage across load resistance |
| D. | number of turns and gauge of secondary winding of transformer |
| Answer» C. current through load and voltage across load resistance | |
| 23. |
Consider the following statements An iron cored choke is a nonlinear device.A carbon resistor kept in a sunlight is a time - invariant and passive device.A dry cell is a time - varying and active device.An air capacitor is a time - invariant and passive device Of these statements |
| A. | 1, 2, 3 and 4 are correct |
| B. | 1, 2 and 3 are correct |
| C. | 1, 2 and 4 are correct |
| D. | 2 and 4 are correct |
| Answer» B. 1, 2 and 3 are correct | |
| 24. |
When the gate terminal of MOSFET is positive, it is said to operate in |
| A. | depletion mode |
| B. | conduction mode |
| C. | enhancement mode |
| D. | none of the above |
| Answer» D. none of the above | |
| 25. |
Assertion (A): In a Schottky diode the reverse recovery time is almost zero. Reason (R): A Schottky diode has aluminium silicon junction. |
| A. | Both A and R are true and R is correct explanation of A |
| B. | Both A and R are true but R is not a correct explanation of A |
| C. | A is true but R is false |
| D. | A is false but R is true |
| Answer» B. Both A and R are true but R is not a correct explanation of A | |
| 26. |
In energy band diagram of p type semiconductor the acceptor energy level is |
| A. | in valence band |
| B. | in conduction band |
| C. | slightly above valence band |
| D. | slightly below conduction band |
| Answer» D. slightly below conduction band | |
| 27. |
Of the various capacitances associated with a junction transistor the gain bandwidth product is affected to maximum extend by |
| A. | base collector parasitic capacitor |
| B. | base collector space charge layer capacitance |
| C. | base emitter space charge layer capacitance |
| D. | base emitter diffusion capacitance |
| Answer» E. | |
| 28. |
The effect of a finite gain of operational amplifier used in an integrator is that |
| A. | it would not integrator |
| B. | slope of the O/P will varied with time |
| C. | final value of the O/P |
| D. | there will be instability in the cirucuit |
| Answer» C. final value of the O/P | |
| 29. |
The ripple factor from a capacitor filter __________ as the load resistance __________ . |
| A. | decreases, decreases |
| B. | decreases, increases |
| C. | increases, decreases |
| D. | increases, increases |
| Answer» C. increases, decreases | |
| 30. |
The diode and the moving coil milliammeter of figure are assumed to be ideal. The meter reading is |
| A. | 0.1 mA |
| B. | <img src="/_files/images/electronics-and-communication-engineering/electronic-devices-and-circuits/55-417-2.png"> |
| C. | <img src="/_files/images/electronics-and-communication-engineering/electronic-devices-and-circuits/55-417-3.png"> |
| D. | <img src="/_files/images/electronics-and-communication-engineering/electronic-devices-and-circuits/55-417-4.png"> |
| Answer» E. | |
| 31. |
From an n channel JFET for VDS constant and if VGS is made more negative, pinch off would occur at |
| A. | higher value of drain current |
| B. | saturation value of drain current |
| C. | zero drain current |
| D. | gate current equal to drain current |
| Answer» D. gate current equal to drain current | |
| 32. |
The V-I characteristic of a semi-conductor diode is shown in figure. From this figure it can be concluded that |
| A. | The diode is a silicon diode |
| B. | The diode is a germanium diode |
| C. | Break down voltage of the diode is 0.7 V |
| D. | At 1 V rated current will pass through the diode |
| Answer» B. The diode is a germanium diode | |
| 33. |
Electrical contact materials used in switches, brushes and relays must possess |
| A. | high thermal conductivity and high melting point |
| B. | low thermal conductivity and low melting point |
| C. | high thermal conductivity and low melting point |
| D. | low thermal conductivity and high melting point |
| Answer» B. low thermal conductivity and low melting point | |
| 34. |
Measurement of Hall coefficient enables the determination of |
| A. | transportation factor decreases and a increases |
| B. | transportation factor increases and a increases |
| C. | transportation factor increases and a decreases |
| D. | transportation factor decreases and a decreases |
| Answer» E. | |
| 35. |
The process of deliberately adding impurity to a semi-conductor material is called |
| A. | impurification |
| B. | pollution |
| C. | deionisation |
| D. | doping |
| Answer» E. | |
| 36. |
Assertion (A): When a zener diode breakdown, occurs the voltage across it is constant. Reason (R): The upper limit of zener current is determined by power handling capacity. |
| A. | Both A and R are true and R is correct explanation of A |
| B. | Both A and R are true but R is not a correct explanation of A |
| C. | A is true but R is false |
| D. | A is false but R is true |
| Answer» C. A is true but R is false | |
| 37. |
In sign magnitude numbers, |
| A. | the leading bit stands for the sign |
| B. | the leading bit is part of the magnitude |
| C. | the leading bit is always 0 |
| D. | the leading bit is always 1 |
| Answer» B. the leading bit is part of the magnitude | |
| 38. |
A/D parallel converter is also called flash converter. |
| A. | True |
| B. | False |
| Answer» B. False | |
| 39. |
In number system e.g. 6, a decade counter has to recycle to 0 at the sixth count. Which of the connections indicate below will realize this resetting? (a logic 0 at the R inputs resets the counters) |
| A. | <img src="/_files/images/electronics-and-communication-engineering/digital-electronics/50-808-1.png"> |
| B. | <img src="/_files/images/electronics-and-communication-engineering/digital-electronics/50-808-2.png"> |
| C. | <img src="/_files/images/electronics-and-communication-engineering/digital-electronics/50-808-3.png"> |
| D. | None of these |
| Answer» D. None of these | |
| 40. |
In 8085 microprocessor, in order to enable INTR interrupt, which of the following instruction are needed? |
| A. | EI only |
| B. | SIM only |
| C. | El and SIM both |
| D. | None |
| Answer» B. SIM only | |
| 41. |
Logic pulser |
| A. | generates short duration pulses |
| B. | generates long duration pulses |
| C. | generates sinusoidal voltage |
| D. | generates ideal pulses |
| Answer» B. generates long duration pulses | |
| 42. |
The MOS symbol shown indicates that It is depletion typeIt is enhancement typeIt is channelIt is P-channelElectrons flow from s to DHoles flow from D to s The true statements are |
| A. | 1, 3, 6 |
| B. | 1, 3, 5 |
| C. | 2, 4, 6 |
| D. | 2, 3, 5 |
| Answer» E. | |
| 43. |
The no. of FF required and the maximum decimal no. of a MOD-12 counter is |
| A. | 12, 12 |
| B. | 4, 11 |
| C. | 3, 6 |
| D. | 4, 10 |
| Answer» C. 3, 6 | |
| 44. |
In a digital counter the number of flip-flops is |
| A. | always 2 |
| B. | always even |
| C. | always odd |
| D. | equal to the number of bits required in the final binary count |
| Answer» D. equal to the number of bits required in the final binary count | |
| 45. |
Assertion (A): Gray code is used in shaft position encoding.Reason (R): In gray code only a single bit change occurs when going from one code to another. |
| A. | Both A and R are correct and R is correct explanation of A |
| B. | Both A and R are correct but R is not correct explanation of A |
| C. | A is true, R is false |
| D. | A is false, R is true |
| Answer» B. Both A and R are correct but R is not correct explanation of A | |
| 46. |
An inductance having XL = 5 &ohm; and a capacitance having XC = 5 &ohm; are connected in parallel across 100 V, 50 Hz supply. The current drawn from source is |
| A. | zero |
| B. | 20 A |
| C. | 40 A |
| D. | 28.28 A |
| Answer» B. 20 A | |
| 47. |
An RLC series circuit is excited by an ac voltage v = 1 sint. If L = 10 H, C = 0.1 F peak value of voltage across R is |
| A. | 0.707 V |
| B. | 1 V |
| C. | 1.44 V |
| D. | indeterminate as value of R is not given |
| Answer» C. 1.44 V | |
| 48. |
The value of the inductance of coil in which a current increases linearly from zero to 0.1A in 0.2 second producing a voltage of 5 volts is __________ . |
| A. | 2.5 |
| B. | 5 |
| C. | 10 |
| D. | 20 |
| Answer» D. 20 | |
| 49. |
If all other parameters are the same, a capacitor with mica as dielectric has higher capacitance than air capacitor. |
| A. | True |
| B. | False |
| Answer» B. False | |
| 50. |
If V = 100 16 , the (V) is |
| A. | 10 32 |
| B. | 10 8 |
| C. | 10 16 |
| D. | 10 4 |
| Answer» C. 10 16 | |