MCQOPTIONS
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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.
| 2901. |
Assertion (A): When a photoconductive device is exposed to light, its bulk resistance increases. Reason (R): When exposed to light, electron hole pairs are generated in the photoconductive device. |
| 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» E. | |
| 2902. |
As comparated to an ordinary p-n diode, the extent of impurity atoms in a tunnel diode |
| A. | is more |
| B. | is less |
| C. | may be more or less |
| D. | is almost the same |
| Answer» B. is less | |
| 2903. |
In active filter circuits, inductances are avoided mainly because they |
| A. | are always associated with some resistance |
| B. | are bulky and unsuitable for miniaturisation |
| C. | are non-linear in nature |
| D. | saturate quickly |
| Answer» C. are non-linear in nature | |
| 2904. |
When a p-n-p transistor is operating in active region, the current in the n region is due to |
| A. | only holes |
| B. | only electrons |
| C. | mainly holes |
| D. | mainly electrons |
| Answer» D. mainly electrons | |
| 2905. |
Consider the following statements: The function of oxide layer in an IC device is to mask against diffusion or non implantinsulate the surface electricallyincrease the melting point of siliconproduce a chemically stable protective layer Of these statements: |
| A. | 1, 2, 3 are correct |
| B. | 1, 3, 4 are correct |
| C. | 2, 3, 4 are correct |
| D. | 1, 2, 4 are correct |
| Answer» E. | |
| 2906. |
As temperature increases the forbidden gap in silicon increases. |
| A. | True |
| B. | False |
| Answer» C. | |
| 2907. |
Assertion (A): Germanium is more commonly used than silicon. Reason (R): Forbidden gap in germanium is less than that in silicon. |
| 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» E. | |
| 2908. |
Which of the following devices has substrate? |
| A. | JFET |
| B. | Depletion Type MOSFET |
| C. | Enhancement type MOSFET |
| D. | Both (b) and (c) |
| Answer» E. | |
| 2909. |
In degenerate p type semiconductor material, the Fermi level, |
| A. | is in the valence band |
| B. | is in conduction band |
| C. | is at the centre in between valence and conduction bands |
| D. | is very near conduction band |
| Answer» B. is in conduction band | |
| 2910. |
Assertion (A): The amount of photoelectric emission depends on the intensity of incident light. Reason (R): Photo electric emission can occur only if frequency of incident light is less than threshold frequency. |
| 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 | |
| 2911. |
The cut in voltage of a diode is nearly equal to |
| A. | applied forward voltage |
| B. | applied reverse voltage |
| C. | barrier potential |
| D. | none of the above |
| Answer» D. none of the above | |
| 2912. |
At room temperature the barrier potential in a silicon diode is |
| A. | 0.1 V |
| B. | 0.3 V |
| C. | 0.7 V |
| D. | 1 V |
| Answer» D. 1 V | |
| 2913. |
Determine the transistor capacitance of a diffused junction varicap diode of a reverse potential of 4.2 V if C(0) = 80 pf and VT = 0.7 V |
| A. | 42 pf |
| B. | 153.03 pf |
| C. | 13.33 pf |
| D. | Data inadequate |
| Answer» B. 153.03 pf | |
| 2914. |
Assertion (A): In a BJT base current is very small. Reason (R): In a BJT recombination in base region is high. |
| 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 | |
| 2915. |
A reverse voltage of 18 V is applied to a semiconductor diode. The voltage across the depletion layer is |
| A. | 0 V |
| B. | 0.7 V |
| C. | about 10 V |
| D. | 18 V |
| Answer» E. | |
| 2916. |
When a p-n junction is reverse biased |
| A. | holes and electrons move away from the junction |
| B. | holes and electrons move towards the junction |
| C. | holes move towards junction and electrons move away from junction |
| D. | holes move away from junction and electrons move towards junction |
| Answer» B. holes and electrons move towards the junction | |
| 2917. |
N-type silicon is obtained by doping silicon with |
| A. | germanium |
| B. | aluminium |
| C. | boron |
| D. | phosphorus |
| Answer» E. | |
| 2918. |
What is the effect of cut in voltage on the wave form of output as compared to input in a semiconductor diode? |
| A. | The duration of output waveform is less than 180 |
| B. | Output voltage is less than input voltage |
| C. | Output voltage is more than input voltage |
| D. | Both (a) and (b) |
| Answer» E. | |
| 2919. |
When a large number of atoms are brought together to form a crystal |
| A. | the energy levels of inner shell electrons are affected appreciably by the presence of other neighbouring atoms. |
| B. | The energy levels of outer shell electrons are affected appreciably by the presence of other neighbouring atoms. |
| C. | the energy levels of both inner and outer shell electrons are affected appreciably by the presence of other neighbouring atoms. |
| D. | none of the above. |
| Answer» C. the energy levels of both inner and outer shell electrons are affected appreciably by the presence of other neighbouring atoms. | |
| 2920. |
If a sample of germanium and a sample of Si have the impurity density and are kept at room temperature then |
| A. | both will have equal value of resistivity |
| B. | both will have equal -ve resistivity |
| C. | resistivity of germanium will be higher than that of silicon |
| D. | resistivity of Si will be higher than of germanium |
| Answer» E. | |
| 2921. |
As temperature increases the number of free electrons and holes in an intrinsic semiconductor |
| A. | increases |
| B. | decreases |
| C. | remains the same |
| D. | may increase or decrease |
| Answer» B. decreases | |
| 2922. |
Assertion (A): A JFET behaves as a resistor when VGS < VP. Reason (R): When VGS < VP, the drain current in a JFET is almost constant. |
| 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 | |
| 2923. |
In a reverse biased P-N junction, the current through the junction increases abruptly at |
| A. | zero voltage |
| B. | 1.2 V |
| C. | 0.72 V |
| D. | breakdown voltage |
| Answer» E. | |
| 2924. |
Dielectric strength of polythene is around |
| A. | 10 kV/mm |
| B. | 40 kV/mm |
| C. | 100 kV/mm |
| D. | 140 kV/mm |
| Answer» C. 100 kV/mm | |
| 2925. |
Resistivity of hard drawn copper is |
| A. | less than that of annealed copper |
| B. | more than that of annealed copper |
| C. | same as that of annealed copper |
| D. | decreasing when temperature increases |
| Answer» C. same as that of annealed copper | |
| 2926. |
In a bipolar junction transistor adc = 0.98, ICO= 2 A and 1B = 15 A. The collector current IC is |
| A. | 635 mA |
| B. | 735 mA |
| C. | 835 mA |
| D. | 935 mA |
| Answer» C. 835 mA | |
| 2927. |
A Si sample is doped with a fixed number of group N impurities. The electron density n is measured from 4 K to 1200 k for the sample. Which one of the following is correct? |
| A. | n remains constant over the temperature range |
| B. | n increases monotonicaliy with increasing temp |
| C. | n increases first remains constant over a range and again increases with increasing temperature |
| D. | n increases show a peak and then decrease with temperature |
| Answer» C. n increases first remains constant over a range and again increases with increasing temperature | |
| 2928. |
Assertion (A): In design of circuit using BJT, a derating factor is used. Reason (R): As the ambient temperature increases, heat dissipation becomes slower. |
| 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 | |
| 2929. |
If the drift velocity of holes under a field gradient of 100 V/m is 5m/sec. Their mobility is |
| A. | 0.05 |
| B. | 0.5 |
| C. | 50 |
| D. | 500 |
| Answer» B. 0.5 | |
| 2930. |
Fermi level in intrinsic semiconductor is at the centre of forbidden energy band. |
| A. | True |
| B. | False |
| Answer» B. False | |
| 2931. |
In a photo transistor the photocurrent is |
| A. | emitter base junction |
| B. | collector base junction |
| C. | collector |
| D. | either (a) or (b) |
| Answer» C. collector | |
| 2932. |
Hall effect is observed in a specimen when it is carrying current and is placed in a magnetic field. The resulting electric field inside the speciment will be in |
| A. | direction normal to both current and magnetic field |
| B. | the direction of current |
| C. | direction antiparallel to magnetic field |
| D. | an arbitrary direction depend upon conductivity |
| Answer» B. the direction of current | |
| 2933. |
In a p-n-p transistor operating in forward active mode |
| A. | base is positive with respect to emitter and collector |
| B. | base is negative with respect to emitter and collector |
| C. | emitter is positive with respect to base and base is positive with respect to collector |
| D. | emitter is negative with respect to base and base is positive with respect to collector |
| Answer» D. emitter is negative with respect to base and base is positive with respect to collector | |
| 2934. |
Consider the following statements. EtchingExposure to UV radiationStrippingDeveloping After a wafer has been coated with photo resist the correct sequence of these steps in photolithography is |
| A. | 2, 4, 3, 1 |
| B. | 2, 4, 1, 3 |
| C. | 4, 2, 1, 3 |
| D. | 3, 2, 3, 1 |
| Answer» D. 3, 2, 3, 1 | |
| 2935. |
If both the emitter base and the collector base junctions of a bipolar transistor are forward biased, the transistor is in the |
| A. | active region |
| B. | saturated region |
| C. | cut off region |
| D. | inverse mode |
| Answer» C. cut off region | |
| 2936. |
In a triode the potential of grid (with respect to cathode) is usually |
| A. | zero |
| B. | negative |
| C. | positive |
| D. | zero or positive |
| Answer» C. positive | |
| 2937. |
The maximum power handling capacity of a resistor depends on |
| A. | total surface area |
| B. | resistance value |
| C. | thermal capacity of the resistor |
| D. | resistivity of the material used in the resistor |
| Answer» D. resistivity of the material used in the resistor | |
| 2938. |
Addition of a small amount of antimony to germanium will result in |
| A. | formation of P-type semiconductor |
| B. | more free electrons than holes in the semiconductor |
| C. | antimony concentrating on the edges of the crystals |
| D. | increased resistance |
| Answer» C. antimony concentrating on the edges of the crystals | |
| 2939. |
The mean life time of carrier may range from 10-9 seconds to hundreds of -seconds. |
| A. | True |
| B. | False |
| Answer» B. False | |
| 2940. |
In which mode of BJT operation are both junctions forward biased? |
| A. | Active |
| B. | Saturation |
| C. | Cut off |
| D. | Reverse active |
| Answer» C. Cut off | |
| 2941. |
Which of the following is known as insulated gate FET? |
| A. | JFET |
| B. | MOSFET |
| C. | Both JFET and MOSFET |
| D. | None of the above |
| Answer» C. Both JFET and MOSFET | |
| 2942. |
Assertion (A): The hybrid p model of a transistor can be reduced to h parameter model and vice versa. Reason (R): Hybrid p and h parameter models are interrelated as both of them describe the same device. |
| 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 | |
| 2943. |
Which impurity atom will give p type semiconductor when added to intrinsic semiconductor? |
| A. | Phosphorus |
| B. | Boron |
| C. | Arsenic |
| D. | Antimony |
| Answer» C. Arsenic | |
| 2944. |
Zener breakdown occurs |
| A. | due to rapture of covalent band |
| B. | mostly in germanium junctions |
| C. | in lightly doped junctions |
| D. | due to thermally generated minority carriers |
| Answer» B. mostly in germanium junctions | |
| 2945. |
An insulator will conduct when the |
| A. | voltage applied is more than the breakdown voltage |
| B. | temperature is raised to very high level |
| C. | either (a) or (b) above |
| D. | none of the above |
| Answer» D. none of the above | |
| 2946. |
A varactor diode is |
| A. | reverse biased |
| B. | forward biased |
| C. | biased to breakdown |
| D. | unbiased |
| Answer» B. forward biased | |
| 2947. |
In intrinsic semiconductor magnitude of free electron and hole concentrations are equal. |
| A. | True |
| B. | False |
| Answer» B. False | |
| 2948. |
A P-N junction offers |
| A. | high resistance in forward as well as reverse direction |
| B. | low resistance in forward as well as reverse direction |
| C. | conducts in forward direction only |
| D. | conducts in reverse direction only |
| Answer» D. conducts in reverse direction only | |
| 2949. |
In modern MOSFETS, the material used for the gate is |
| A. | high purity silicon |
| B. | high purity silica |
| C. | heavily doped polycrystalline silicon |
| D. | epitaxial grown silicon |
| Answer» D. epitaxial grown silicon | |
| 2950. |
Consider the following circuit configuration common Emittercommon Baseemitter followeremitter follower using Darlington pair. The correct sequence in increasing order of I/P impedance of these configuration: |
| A. | 2, 1, 4, 3 |
| B. | 1, 2, 4, 3 |
| C. | 2, 1, 3, 4 |
| D. | 1, 2, 3, 4 |
| Answer» C. 2, 1, 3, 4 | |