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MCQOPTIONS
This section includes 9294 Mcqs, each offering curated multiple-choice questions to sharpen your Engineering knowledge and support exam preparation. Choose a topic below to get started.
| 4001. |
The inductance of a single layer solenoid of 10 turns is 5 H. Which one of the following is the correct value of inductance when the number of turns is 20 and the length is doubled. |
| A. | 10 H |
| B. | 20 H |
| C. | 40 H |
| D. | 5 H |
| Answer» B. 20 H | |
| 4002. |
Power diodes are generally |
| A. | silicon diodes |
| B. | germanium diodes |
| C. | either of the above |
| D. | none of the above |
| Answer» B. germanium diodes | |
| 4003. |
The depletion layer width of Junction |
| A. | decreases with light doping |
| B. | is independent of applied voltage |
| C. | is increased under reverse bias |
| D. | increases with heavy doping |
| Answer» D. increases with heavy doping | |
| 4004. |
Forbidden energy gap in germanium at 0 K is about |
| A. | 10 eV |
| B. | 5 eV |
| C. | 2 eV |
| D. | 0.78 eV |
| Answer» E. | |
| 4005. |
Light dependent resistors are |
| A. | highly doped semiconductor |
| B. | intrinsic semiconductor |
| C. | lightly doped semiconductor |
| D. | either (a) or (c) |
| Answer» D. either (a) or (c) | |
| 4006. |
When diodes are connected in series to increase voltage rating the peak inverse voltage per junction |
| A. | should not exceed half the breakdown voltage |
| B. | should not exceed the breakdown voltage |
| C. | should not exceed one third the breakdown voltage |
| D. | may be equal to or less than breakdown voltage |
| Answer» D. may be equal to or less than breakdown voltage | |
| 4007. |
Hall effect is observed in a specimen when it is carrying current and is placed in a magnetic field. The resultant electric field inside the specimen is |
| A. | normal to both current and magnetic field |
| B. | in the direction of current |
| C. | antiparallel to magnetic field |
| D. | in arbitrary direction |
| Answer» B. in the direction of current | |
| 4008. |
In an ideal diode there is no breakdown, no __________ current, and no forward __________ drop. |
| A. | reverse, voltage |
| B. | forward, current |
| C. | forward, voltage |
| D. | reverse, current |
| Answer» B. forward, current | |
| 4009. |
Silicon is not suitable for fabrication of light emitting diodes because it is |
| A. | an indirect band gap semiconductor |
| B. | direct band gap semiconductor |
| C. | wideband gap semiconductor |
| D. | narrowband gap semiconductor |
| Answer» B. direct band gap semiconductor | |
| 4010. |
MOSFET can be used as a |
| A. | current controlled capacitor |
| B. | voltage controlled capacitor |
| C. | current controlled inductor |
| D. | voltage controlled inductor |
| Answer» C. current controlled inductor | |
| 4011. |
For a UJT ifR1 = Resistor from emitter to the base 1R2 = Resistor from emitter to the base 2 and RBB = R1 + R2, then the intrinsic stand off ratio ( ) is |
| A. | <img src="/_files/images/electronics-and-communication-engineering/electronic-devices-and-circuits/60-506-1.png"> |
| B. | <img src="/_files/images/electronics-and-communication-engineering/electronic-devices-and-circuits/60-506-2.png"> |
| C. | <img src="/_files/images/electronics-and-communication-engineering/electronic-devices-and-circuits/60-506-3.png"> |
| D. | <img src="/_files/images/electronics-and-communication-engineering/electronic-devices-and-circuits/60-506-4.png"> |
| Answer» E. | |
| 4012. |
The dynamic resistance of a forward biased p-n diode |
| A. | varies inversely with current |
| B. | varies directly with current |
| C. | is constant |
| D. | is either constant or varies directly with current |
| Answer» B. varies directly with current | |
| 4013. |
A thermistor is a |
| A. | thermocouple |
| B. | thermometer |
| C. | miniature resistance |
| D. | heat sensitive explosive |
| Answer» D. heat sensitive explosive | |
| 4014. |
Maximum rectification efficiency for a half wave rectifier is |
| A. | 100% |
| B. | 88% |
| C. | 50% |
| D. | 40.6% |
| Answer» E. | |
| 4015. |
For a semiconductor, the conductivity is a function of the products of the number of charge carriers and their mobilites. As result, if the temperature of a slab of intrinsic silicon increases, how does its conductivity vary? |
| A. | Decreases |
| B. | Increases |
| C. | Remains unaffected |
| D. | Increases or decreases depending upon the rise in temperature |
| Answer» C. Remains unaffected | |
| 4016. |
In a junction transistor, the collector cut-off current 'ICB0' reduces considerably by doping the |
| A. | emitter with high level of impurity |
| B. | emitter with low level of impurity |
| C. | collector with high level of impurity |
| D. | collector with low level of impurity |
| Answer» B. emitter with low level of impurity | |
| 4017. |
A Schottky diode clamp is used along with a switching BJT for |
| A. | reducing the power |
| B. | reducing the switching time dissipation |
| C. | increasing the value of |
| D. | reducing the base current |
| Answer» C. increasing the value of | |
| 4018. |
For a NPN bipolar transistor, what is the main stream of current in the base region? |
| A. | Drift of holes |
| B. | Diffusion of holes |
| C. | Drift of electrons |
| D. | Diffusion of electrons |
| Answer» C. Drift of electrons | |
| 4019. |
Assertion (A): A VMOS can handle much larger current than other field effect transistors. Reason (R): In a VMOS the conducting channel is very narrow. |
| 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» D. A is false but R is true | |
| 4020. |
In monolithic ICs, all the components are fabricated by |
| A. | diffusion process |
| B. | oxidation |
| C. | evaporation |
| D. | none |
| Answer» B. oxidation | |
| 4021. |
Which one of the following is not a characteristic of a ferroelectric material? |
| A. | High dielectric constant |
| B. | No hysteresis |
| C. | Ferroelectric characteristic only above the curie point |
| D. | Electric dipole moment |
| Answer» D. Electric dipole moment | |
| 4022. |
In a bipolar transistor, the base collector junction has |
| A. | forward bias |
| B. | reverse bias |
| C. | zero bias |
| D. | zero or forward bias |
| Answer» C. zero bias | |
| 4023. |
An intrinsic silicon sample has 1 million free electrons at room temperature. As the temperature is increased |
| A. | the number of free electrons increases |
| B. | the number of free electrons increases but the number of holes decreases |
| C. | the number of free electrons and holes increase by the same amount |
| D. | the number of free electrons and holes increase but not by the same amount |
| Answer» D. the number of free electrons and holes increase but not by the same amount | |
| 4024. |
Which of these are universal gates? |
| A. | Only NOR |
| B. | Only NAND |
| C. | Both NOR and NAND |
| D. | NOR, NAND, OR |
| Answer» D. NOR, NAND, OR | |
| 4025. |
Out of latch and flip flop, which has clock input? |
| A. | Latch only |
| B. | Flip flop only |
| C. | Both latch and flip flop |
| D. | None |
| Answer» C. Both latch and flip flop | |
| 4026. |
A mod 4 counter will count |
| A. | from 0 to 4 |
| B. | from 0 to 3 |
| C. | from any number n to n + 4 |
| D. | none of the above |
| Answer» C. from any number n to n + 4 | |
| 4027. |
Which of the following finds application in pocket calculators? |
| A. | TTL |
| B. | CMOS |
| C. | ECL |
| D. | Both (a) and (c) |
| Answer» C. ECL | |
| 4028. |
The total number of input words for 4 input OR gate is |
| A. | 20 |
| B. | 16 |
| C. | 12 |
| D. | 8 |
| Answer» C. 12 | |
| 4029. |
In the given figure shows a 4 bit serial in parallel out right shift register. The initial contents as shown are 0110. After 3 clock pulses the contents will be |
| A. | 0000 |
| B. | 0101 |
| C. | 1010 |
| D. | 1111 |
| Answer» D. 1111 | |
| 4030. |
In digital circuits Schottky transistors are preferred over normal transistors because of their |
| A. | lower propagation delay |
| B. | lower power dissipation |
| C. | higher propagation delay |
| D. | higher power dissipation |
| Answer» B. lower power dissipation | |
| 4031. |
A flip flop is a |
| A. | combinational circuit |
| B. | memory element |
| C. | arithmetic element |
| D. | memory or arithmetic element |
| Answer» C. arithmetic element | |
| 4032. |
A 4 bit parallel type A/D converter uses a 6 volt reference. How many comparators are required and what is the resolution in volts? |
| A. | 0.375 V |
| B. | 15 V |
| C. | 4.5 V |
| D. | 10 V |
| Answer» B. 15 V | |
| 4033. |
Quantization error occurs in |
| A. | D/A converter |
| B. | A/D converter |
| C. | both D/A and A/D converter |
| D. | neither D/A nor A/D converter |
| Answer» C. both D/A and A/D converter | |
| 4034. |
Which display device resembles vacuum tube? |
| A. | LED |
| B. | LCD |
| C. | VF |
| D. | None of these |
| Answer» D. None of these | |
| 4035. |
The number of inputs and outputs of a full adder are |
| A. | 3 and 2 respectively |
| B. | 2 and 3 respectively |
| C. | 4 and 2 respectively |
| D. | 2 and 4 respectively |
| Answer» B. 2 and 3 respectively | |
| 4036. |
The dual of A + [B + (AC)] + D is |
| A. | A + [(B (A + C))] + D |
| B. | A [B + AC] D |
| C. | A + [B (A + C)] D |
| D. | A [B (A + C)] D |
| Answer» E. | |
| 4037. |
A divide by 78 counter can be obtained by |
| A. | 6 numbers of mod-13 counters |
| B. | 13 numbers of mod-6 counters |
| C. | one mod-13 counter followed by mod-6 counter |
| D. | 13 number of mod-13 counters |
| Answer» D. 13 number of mod-13 counters | |
| 4038. |
The initial state of MOD-16 down counter is 0110. What state will it be after 37 clock pulses? |
| A. | Indeterminate |
| B. | 0110 |
| C. | 0101 |
| D. | 0001 |
| Answer» E. | |
| 4039. |
The number of address lines in EPROM 4096 x 8 is |
| A. | 2 |
| B. | 4 |
| C. | 8 |
| D. | 12 |
| Answer» E. | |
| 4040. |
If the inputs to a 3 bit binary adder are 1112 and 1112, the output will be 1102 |
| A. | True |
| B. | False |
| Answer» C. | |
| 4041. |
Which of these are two state devices? |
| A. | Lamp |
| B. | Punched card |
| C. | Magnetic tape |
| D. | All of the above |
| Answer» E. | |
| 4042. |
The Boolean expression for the circuit of the given figure |
| A. | A {F + (B + C) (D + E)} |
| B. | A [F + (B + C) (DE)] |
| C. | A + F + (B + C) (D + E)] |
| D. | A [F + (BC) (DE)] |
| Answer» B. A [F + (B + C) (DE)] | |
| 4043. |
What will be minimum conversion rate in 6 bit dual slope A/D converter uses a reference of -6v and a 1 MHz clock. It uses a fixed count of 40 (101000). |
| A. | 9000 |
| B. | 9259 |
| C. | 1000 |
| D. | 1000 |
| Answer» C. 1000 | |
| 4044. |
The first machine cycle of an instruction is always |
| A. | a memory read cycle |
| B. | a fetch cycle |
| C. | a input/output read cycle |
| D. | a memory write cycle |
| Answer» C. a input/output read cycle | |
| 4045. |
What will be BCD number when the output is 0.37 V? |
| A. | 00110111 |
| B. | 10110111 |
| C. | 11001000 |
| D. | 01001000 |
| Answer» B. 10110111 | |
| 4046. |
A counter has N flip flops. The total number of states are |
| A. | N |
| B. | 2 N |
| C. | 2 |
| D. | <sup>N</sup> |
| E. | 4 N |
| Answer» D. <sup>N</sup> | |
| 4047. |
Out of S, R, J, K, Preset, Clear inputs to flip flops, the synchronous inputs are |
| A. | S, R, J, K only |
| B. | S, R, Preset, Clear only |
| C. | Preset, Clear only |
| D. | S, R only |
| Answer» B. S, R, Preset, Clear only | |
| 4048. |
For the binary number 11101000, the equivalent hexadecimal number is |
| A. | F 9 |
| B. | F 8 |
| C. | E 9 |
| D. | E 8 |
| Answer» E. | |
| 4049. |
A Karnaugh map with 4 variables has |
| A. | 2 cells |
| B. | 4 cells |
| C. | 8 cells |
| D. | 16 cells |
| Answer» E. | |
| 4050. |
Wired AND connection can be used in TTL with totem pole output. |
| A. | True |
| B. | False |
| Answer» C. | |