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.
| 3051. |
Which of these has highly doped p and n region? |
| A. | PIN diode |
| B. | Tunnel diode |
| C. | Schottky diode |
| D. | Photodiode |
| Answer» C. Schottky diode | |
| 3052. |
The threshold voltage of an n-channel enhancement mode MOSFET is 0.5 when the device is biased at a gate voltage of 3V. Pinch off would occur at a drain voltage of |
| A. | 1.5 V |
| B. | 2.5 V |
| C. | 3.5 V |
| D. | 4.5 V |
| Answer» C. 3.5 V | |
| 3053. |
Which of these has degenerate p and n materials? |
| A. | Zener diode |
| B. | PIN diode |
| C. | Tunnel diode |
| D. | Photo diode |
| Answer» D. Photo diode | |
| 3054. |
A Schottky diode clamp is used along with switching BJT for |
| A. | reducing the power dissipation |
| B. | reducing the switching time |
| C. | increasing the value of |
| D. | reducing the base current |
| Answer» C. increasing the value of | |
| 3055. |
Which of the following is basically a voltage controlled capacitance? |
| A. | Zener diode |
| B. | Diode |
| C. | Varactor diode |
| D. | LED |
| Answer» D. LED | |
| 3056. |
When the i-v curve of a photodiode passes through origin the illumination is |
| A. | maximum |
| B. | minimum |
| C. | zero |
| D. | equal to rated value |
| Answer» D. equal to rated value | |
| 3057. |
In which device does the extent of light controls the conduction |
| A. | photovoltaic cell |
| B. | photo electric relay |
| C. | LED |
| D. | photo sensitive device |
| Answer» E. | |
| 3058. |
The threshold voltage of a MOSFET can be lowered by using thin gate oxidereducing the substrate concentrationincreasing the substrate concentration. Of the above statement |
| A. | 3 alone is correct |
| B. | 1 and 2 are correct |
| C. | 1 and 3 are correct |
| D. | 2 alone is correct |
| Answer» D. 2 alone is correct | |
| 3059. |
In a piezoelectric crystal, applications of a mechanical stress would produce |
| A. | plastic deformation of the crystal |
| B. | magnetic dipoles in the crystal |
| C. | electrical polarization in the crystal |
| D. | shift in the Fermi level |
| Answer» D. shift in the Fermi level | |
| 3060. |
An one sided abrupt junction has 1021/m3 of dopants on the lightly doped side, zero bias voltage and a built-in potential of 0.2 V. The depletion width of abrupt junction.(q = 1.6 x 10-19 C, r =16, 0 = 8.87 x 10-12 F/m) is |
| A. | 0.036 nm |
| B. | 0.6 m |
| C. | 3 mm |
| D. | 1.5 mm |
| Answer» C. 3 mm | |
| 3061. |
n-type semiconductors |
| A. | are negatively charged |
| B. | are produced when indium is added as impurity to germanium |
| C. | are produced when phosphorus is added as impurity to silicon |
| D. | none of the above |
| Answer» D. none of the above | |
| 3062. |
In all metals |
| A. | conductivity decreases with increase in temperature |
| B. | current flow by electrons as well as by holes |
| C. | resistivity decreases with increase in temperature |
| D. | the gap between valence and conduction bands is small |
| Answer» B. current flow by electrons as well as by holes | |
| 3063. |
The voltage across a zener diode |
| A. | is constant in forward direction |
| B. | is constant in reverse direction |
| C. | is constant in both forward and reverse directions |
| D. | none of the above |
| Answer» C. is constant in both forward and reverse directions | |
| 3064. |
Assertion (A): Two transistors one n-p-n and the other p-n-p are identical in all respects (doping, construction, shape, size). The n-p-n transistor will have better frequency response. Reason (R): The electron mobility is higher than hole mobility. |
| 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 | |
| 3065. |
The units for transconductance are |
| A. | ohms |
| B. | amperes |
| C. | volts |
| D. | siemens |
| Answer» E. | |
| 3066. |
Two identical silicon diodes D1 and D2 are connected back to back shown in figure. The reverse saturation current Is of each diode is 10-8 amps and the breakdown voltage VBr is 50 v. Evaluate the voltages VD1 and VD2 dropped across the diodes D1 and D2 assuming KT/q to be 25 m V. |
| A. | 4.983 V, 0.017 V |
| B. | - 4.98 V, - 0.017 V |
| C. | 0.17 V, 4.983 V |
| D. | - 0.017 V, - 4.98 V |
| Answer» C. 0.17 V, 4.983 V | |
| 3067. |
When a p-n-p transistor is properly biased to operate in active region the holes from emitter. |
| A. | diffuse through base into collector region |
| B. | recombine with electrons in base |
| C. | recombine with electrons in emitter |
| D. | none of the above |
| Answer» B. recombine with electrons in base | |
| 3068. |
Assertion (A): Silicon is preferred over germanium in manufacture of semiconductor devices. Reason (R): Forbidden gap in silicon is more than that in germanium. |
| 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 | |
| 3069. |
Assertion (A): A decrease in temperature increases the reverse saturation current in a p-n diode. Reason (R): When a diode is reverse biased surface leakage current flows. |
| 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. | |
| 3070. |
At room temperature a semiconductor material is |
| A. | perfect insulator |
| B. | conductor |
| C. | slightly conducting |
| D. | any of the above |
| Answer» D. any of the above | |
| 3071. |
Introducing a resistor in the emitter of a common amplifier stabilizes the d.c. operating point against variations in |
| A. | only the temperature |
| B. | only of the transistor |
| C. | both temperature and |
| D. | none of these |
| Answer» D. none of these | |
| 3072. |
If the gate of JFET is reverse biased, the width of depletion region |
| A. | becomes zero |
| B. | is uniform |
| C. | is more near the source |
| D. | is more near the drain |
| Answer» E. | |
| 3073. |
Which of the following semi-conductor has forbidden energy gap less 1 eV? |
| A. | Sulphur |
| B. | Phosphorous |
| C. | Germanium |
| D. | Carbon |
| Answer» D. Carbon | |
| 3074. |
In the vacuum diode equation ib = keb1.5, the current is |
| A. | temperature limited current |
| B. | space charge limited current |
| C. | any of the above |
| D. | none of the above |
| Answer» C. any of the above | |
| 3075. |
Thermosetting polymers are |
| A. | injection moulded |
| B. | extruded |
| C. | cast moulded |
| D. | none of the above |
| Answer» D. none of the above | |
| 3076. |
Which of these is used in seven segment display? |
| A. | PIN diode |
| B. | LED |
| C. | Photo diode |
| D. | Tunnel diode |
| Answer» C. Photo diode | |
| 3077. |
The impurity added to extrinsic semiconductor is of the order of |
| A. | 1 in 100 |
| B. | 1 in 1000 |
| C. | 1 in 100, 0000 |
| D. | 1 in 100, 000, 000 |
| Answer» E. | |
| 3078. |
In a bipolar transistor |
| A. | the base is thick and highly doped |
| B. | the base is thin and highly doped |
| C. | the base is thick and lightly doped |
| D. | the base is thin and lightly doped |
| Answer» E. | |
| 3079. |
Which of the following materials has the highest electrical conductivity? |
| A. | Steel |
| B. | Silver |
| C. | Aluminium |
| D. | Zinc |
| Answer» C. Aluminium | |
| 3080. |
The impurity commonly used for realizing the base region of a n-p-n transistor is |
| A. | gallium |
| B. | indium |
| C. | boron |
| D. | phosphorus |
| Answer» D. phosphorus | |
| 3081. |
Hay bridge is suitable for measuring inductance of which one of the following inductors? |
| A. | Having Q value less than 10 |
| B. | Having Q value greater than 10 |
| C. | Having any value of Q |
| D. | Having phase angle of reactance very large |
| Answer» C. Having any value of Q | |
| 3082. |
When a substance is repelled by a magnetic field it is known as |
| A. | ferromagnetic |
| B. | antiferromagnetic |
| C. | diamagnetic |
| D. | paramagnetic |
| Answer» D. paramagnetic | |
| 3083. |
An incremental model of a solid state device is one which represents the |
| A. | ac property of the device at desired operating point |
| B. | dc property of the device at all operating points |
| C. | complete ac and dc behaviour at all operating points |
| D. | ac property of the device at all operating points |
| Answer» B. dc property of the device at all operating points | |
| 3084. |
Which of the following is used for generating time varying wave forms? |
| A. | MOSFET |
| B. | PIN diode |
| C. | Tunnel diode |
| D. | UJT |
| Answer» E. | |
| 3085. |
For an n-channel enhancement type MOSFET, if the source is connected at a higher potential than that of the bulk (VSB > 0), the threshold voltage VT of the MOSFET will |
| A. | remain unchanged |
| B. | decrease |
| C. | change Polarity |
| D. | increase |
| Answer» B. decrease | |
| 3086. |
What is the correct sequence of the following step in the fabrication of a monolithic, Bipolar junction transistor? Emitter diffusionBase diffusionBuried layer formationE pi-layer formation Select the correct answer using the codes given below: |
| A. | 3, 4, 1, 2 |
| B. | 4, 3, 1, 2 |
| C. | 3, 4, 2, 1 |
| D. | 4, 3, 2, 1 |
| Answer» E. | |
| 3087. |
Calculate the resistivity of n-type semiconductor from the following data, Density of holes = 5 x 1012 cm-3. Density of electrons = 8 x 1013 cm-3, mobility of conduction electron = 2.3 x 104 cm2/ V-sec and mobility of holes = 100 cm2/V-sec. |
| A. | 0.43 Ω-m |
| B. | 0.34 Ω-m |
| C. | 0.42 Ω-m |
| D. | 0.24 Ω-m |
| Answer» C. 0.42 Ω-m | |
| 3088. |
A full wave bridge rectifier is supplied voltage at 50 Hz. The lowest ripple frequency will be |
| A. | 400 Hz |
| B. | 200 Hz |
| C. | 100 Hz |
| D. | 50 Hz |
| Answer» D. 50 Hz | |
| 3089. |
Carbon resistances are used in very high values. |
| A. | True |
| B. | False |
| Answer» B. False | |
| 3090. |
At resonance, the parallel circuit constituted by an iron-cored coil and a capacitor behaves like |
| A. | open circuit |
| B. | short circuit |
| C. | pure resistor of value R |
| D. | pure resistor of value much higher than R |
| Answer» E. | |
| 3091. |
An RC impadence function has a pole at s = 0. The first element in the Foster form of synthesis |
| A. | is R |
| B. | may be R and C |
| C. | is C |
| D. | is R and C in parallel |
| Answer» C. is C | |
| 3092. |
The frequency at which maximum voltage occurs across the capacitance in R-L-C series circuits is given by |
| A. | <img src="/_files/images/electronics-and-communication-engineering/networks-analysis-and-synthesis/150-1091-1.png"> |
| B. | <img src="/_files/images/electronics-and-communication-engineering/networks-analysis-and-synthesis/150-1091-2.png"> |
| C. | <img src="/_files/images/electronics-and-communication-engineering/networks-analysis-and-synthesis/150-1091-3.png"> |
| D. | <img src="/_files/images/electronics-and-communication-engineering/networks-analysis-and-synthesis/150-1091-4.png"> |
| Answer» B. <img src="/_files/images/electronics-and-communication-engineering/networks-analysis-and-synthesis/150-1091-2.png"> | |
| 3093. |
0 = 8.85 x 10-12F/m. |
| A. | True |
| B. | False |
| Answer» B. False | |
| 3094. |
A series RC circuit has fixed XC, and variable R. The current locus is in the first quadrant. |
| A. | True |
| B. | False |
| Answer» B. False | |
| 3095. |
One limitation of constant k filters is that Z0 is not constant in the pass band. |
| A. | True |
| B. | False |
| Answer» B. False | |
| 3096. |
Consider the following statements:The klystron and travelling wave tube differ from each other, In TWT the microwave circuit is non- resonant.In klystron the microwave circuit is resonant.TWT uses attenuator.The wave is TWT is a non-propagating wave. Which of the above statements are correct? |
| A. | 1 and 2 only |
| B. | 3 and 4 only |
| C. | 1, 2 and 3 |
| D. | 2, 3 and 4 |
| Answer» D. 2, 3 and 4 | |
| 3097. |
Consider the function 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 |
| Answer» E. | |
| 3098. |
In figure, the current through 2 &ohm; resistance is |
| A. | zero |
| B. | -2A |
| C. | 2A |
| D. | 1A |
| Answer» B. -2A | |
| 3099. |
Given , and f(t)t is . The value of k is |
| A. | 3/16 |
| B. | 16/3 |
| C. | 3 |
| D. | 1/4 |
| Answer» C. 3 | |
| 3100. |
In a one port network . It is excited by a unit step current. The initial and final values of voltage across the network impedance are |
| A. | <img src="/_files/images/electronics-and-communication-engineering/networks-analysis-and-synthesis/101-329-2.png"> |
| B. | <img src="/_files/images/electronics-and-communication-engineering/networks-analysis-and-synthesis/101-329-3.png"> |
| C. | <img src="/_files/images/electronics-and-communication-engineering/networks-analysis-and-synthesis/101-329-4.png"> |
| D. | 1 and 0 |
| Answer» B. <img src="/_files/images/electronics-and-communication-engineering/networks-analysis-and-synthesis/101-329-3.png"> | |