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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.
| 4151. |
In a bipolar transistor, the emitter base junction has |
| A. | forward bias |
| B. | reverse bias |
| C. | zero bias |
| D. | zero or reverse bias |
| Answer» B. reverse bias | |
| 4152. |
The network shown in the figure represents a |
| A. | band pass filter |
| B. | low pass filter |
| C. | high pass filter |
| D. | band stop filter |
| Answer» B. low pass filter | |
| 4153. |
Which of these has semi-conductor metal junction? |
| A. | PIN diode |
| B. | Photo diode |
| C. | Tunnel diode |
| D. | Schottky diode |
| Answer» E. | |
| 4154. |
The ripple factor of power supply is a measure of |
| A. | its filter efficiency |
| B. | diode rating |
| C. | its voltage regulation |
| D. | purity of power output |
| Answer» E. | |
| 4155. |
Figure represents a |
| A. | Diode rectifier |
| B. | Schottky diode |
| C. | Varistor |
| D. | None of the above |
| Answer» C. Varistor | |
| 4156. |
The output, V-I characteristics of an Enhancement type MOSFET has |
| A. | only an ohmic region |
| B. | only a saturation region |
| C. | an ohmic region at low voltage value followed by a saturation region at higher voltages |
| D. | an ohmic region at large voltage values preceded by a saturation region at lower voltages |
| Answer» D. an ohmic region at large voltage values preceded by a saturation region at lower voltages | |
| 4157. |
The forbidden energy gap between the valence band and conduction band will be least in case of |
| A. | metals |
| B. | semiconductors |
| C. | insulators |
| D. | all of the above |
| Answer» B. semiconductors | |
| 4158. |
If too large current passes through the diode |
| A. | all electrons will leave |
| B. | all holes will freeze |
| C. | excessive heat may damage the diode |
| D. | diode will emit light |
| Answer» D. diode will emit light | |
| 4159. |
Amplification of ultrasonic waves is possible in a piezoelectric semiconductor under applied electric field. The basic phenomenon involved is known as |
| A. | electrostriction |
| B. | acousto-optic interaction |
| C. | acousto-electric interaction |
| D. | stimulated Brillouin scattering |
| Answer» D. stimulated Brillouin scattering | |
| 4160. |
For a junction FET in the pinch off region, as the drain voltage is increased, the drain current |
| A. | becomes zero |
| B. | abruptly decrease |
| C. | abruptly increases |
| D. | remains constant |
| Answer» E. | |
| 4161. |
In which mode of BJT operation are both junctions reverse biased? |
| A. | Active |
| B. | Saturation |
| C. | Cut off |
| D. | Reverse active |
| Answer» D. Reverse active | |
| 4162. |
A CMOS amplifier when compared to an N-channel. MOSFET, has the advantage of |
| A. | higher cut off frequency |
| B. | higher voltage gain |
| C. | higher current gain |
| D. | lower current drain from the power supply, there by less dissipation |
| Answer» B. higher voltage gain | |
| 4163. |
Dynamic resistance of diode is |
| A. | True |
| B. | False |
| Answer» B. False | |
| 4164. |
The presence of some holes in an intrinsic semiconductor at room temperature is due to |
| A. | valence electrons |
| B. | doping |
| C. | free electrons |
| D. | thermal energy |
| Answer» E. | |
| 4165. |
For an insulating material, dielectric strength and dielectric loss should be respectively |
| A. | high and high |
| B. | low and high |
| C. | high and low |
| D. | low and low |
| Answer» D. low and low | |
| 4166. |
With an ac input from 50 Hz power line, the ripple frequency is |
| A. | 50 Hz in the dc output of half wave as well as full wave rectifier |
| B. | 100 Hz in the dc output of half wave as well as full wave rectifier |
| C. | 50 Hz in the dc output of half wave and 100 Hz in the dc output of full wave |
| D. | 100 Hz in the dc output of half wave and 50 Hz in the dc output of full wave |
| Answer» D. 100 Hz in the dc output of half wave and 50 Hz in the dc output of full wave | |
| 4167. |
Semiconductors have |
| A. | aero temperature coefficient of resistance |
| B. | positive temperature coefficient of resistance |
| C. | negative temperature coefficient of resistance |
| D. | none of the above |
| Answer» D. none of the above | |
| 4168. |
In the equation i = I0 (eV/ VT - 1), VT = |
| A. | <img src="/_files/images/electronics-and-communication-engineering/electronic-devices-and-circuits/41-121-1.png"> |
| B. | <img src="/_files/images/electronics-and-communication-engineering/electronic-devices-and-circuits/41-121-2.png"> |
| C. | T x 11600 |
| D. | <img src="/_files/images/electronics-and-communication-engineering/electronic-devices-and-circuits/41-121-3.png"> |
| Answer» C. T x 11600 | |
| 4169. |
In the forward blocking region of a silicon, controlled rectifier, the SCR is |
| A. | in the off-state |
| B. | in the ON state |
| C. | reverse biased |
| D. | at the point of breakdown |
| Answer» B. in the ON state | |
| 4170. |
Which of the following is a passive component? |
| A. | Semiconductor devices |
| B. | Vacuum tube devices |
| C. | Capacitors |
| D. | All of the above |
| Answer» D. All of the above | |
| 4171. |
The product kT (where k is Boltzmann's constant and T is absolute temperature) at room temperature is about |
| A. | 0.051 eV |
| B. | 0.026 eV |
| C. | 0.01 eV |
| D. | 0.001 eV |
| Answer» C. 0.01 eV | |
| 4172. |
Which variety of copper has the best conductivity? |
| A. | Pure annealed copper |
| B. | Hard drawn copper |
| C. | Induction hardened copper |
| D. | Copper containing traces of silicon |
| Answer» B. Hard drawn copper | |
| 4173. |
The number of valence electrons in a silicon atom is |
| A. | 4 |
| B. | 2 |
| C. | 1 |
| D. | 0 |
| Answer» B. 2 | |
| 4174. |
In a JFET VDS exceeds the rated value. Then it operates in |
| A. | active region |
| B. | ohmic region |
| C. | cut off region |
| D. | either cut off or active region |
| Answer» D. either cut off or active region | |
| 4175. |
To ensure that a zener diode does not get destroyed |
| A. | the applied voltage should not exceed breakdown voltage |
| B. | the current should not exceed rated current |
| C. | the current should be less than magnitude of barrier potential |
| D. | both (a) and (b) |
| Answer» C. the current should be less than magnitude of barrier potential | |
| 4176. |
The ratio of impurity atoms to intrinsic semiconductor atoms in an extrinsic semiconductor is about. |
| A. | 1 : 10 |
| B. | 1 : 1000 |
| C. | 1 : 100000 |
| D. | 1 : 10 |
| E. | <sup>8</sup> |
| Answer» E. <sup>8</sup> | |
| 4177. |
The turn on time of an SCR is 5 micro second. Its trigger pulse should have |
| A. | short rise time with pulse width = 2.5 s |
| B. | long rise time with pulse width = 3 s |
| C. | short rise time with pulse width = 4 s |
| D. | long rise time with pulse width = 4 s |
| Answer» D. long rise time with pulse width = 4 s | |
| 4178. |
In the circuit of figure the current through 5 &ohm; resistance at t = is |
| A. | 4 A |
| B. | 2.5 A |
| C. | 3.1 A |
| D. | 0 A |
| Answer» C. 3.1 A | |
| 4179. |
For maximum transfer of power, internal resistance of the source should be |
| A. | equal to load resistance |
| B. | less than the load resistance |
| C. | greater than the load resistance |
| D. | none of the above |
| Answer» B. less than the load resistance | |
| 4180. |
Nichrome is used in |
| A. | heater coils |
| B. | underground cables |
| C. | overheated wires |
| D. | lamp filament |
| Answer» B. underground cables | |
| 4181. |
If Va1 = Va2 = 100 V and Va0 = 0, then Va, Vb, Vc are |
| A. | 200, -100 and -100 V |
| B. | 100, 100, 300 V |
| C. | 200, 100, 100 V |
| D. | 100, -100, 100 V |
| Answer» B. 100, 100, 300 V | |
| 4182. |
Assertion (A): A series RLC circuit resonates when excited by variable frequency source.Reason (R): Resonant frequency is geometric mean of half power frequencies. |
| A. | Both A and R are true and R is correct explanation of A |
| B. | Both A and R are true and R is not the 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 | |
| 4183. |
In figure, the switch S is initially open and steady state conditions are reached. At t = 0 switch is closed. The initial current through 2C capacitor is |
| A. | zero |
| B. | 1 A |
| C. | 2 A |
| D. | 3 A |
| Answer» C. 2 A | |
| 4184. |
For an RC driving point impedance function, the poles and zeros |
| A. | should alternate on real axis |
| B. | should alternate only on negative real axis |
| C. | should alternate on imaginary axis |
| D. | none of the above |
| Answer» B. should alternate only on negative real axis | |
| 4185. |
The time constant of an R.C. circuit increases if the value of resistance is |
| A. | increased |
| B. | decreased |
| C. | either of the above |
| D. | none of the above |
| Answer» B. decreased | |
| 4186. |
For the wave shown in figure, the average value is |
| A. | 14.14 A |
| B. | 15 A |
| C. | 17.17 A |
| D. | 19.19 A |
| Answer» C. 17.17 A | |
| 4187. |
The dc voltage applied to an R-L series circuit is suddenly changed from V1 to V2. The expression for transient current is |
| A. | <img src="/_files/images/electronics-and-communication-engineering/networks-analysis-and-synthesis/110-501-1.png"> |
| B. | <img src="/_files/images/electronics-and-communication-engineering/networks-analysis-and-synthesis/110-501-2.png"> |
| C. | <img src="/_files/images/electronics-and-communication-engineering/networks-analysis-and-synthesis/110-501-3.png"> |
| D. | either (a) or (c) |
| Answer» D. either (a) or (c) | |
| 4188. |
When R and C are connected in parallel, phase angle of Y is positive. |
| A. | True |
| B. | False |
| Answer» B. False | |
| 4189. |
One ampere means the flow of |
| A. | One coulomb each minute |
| B. | One electron per second |
| C. | One coulomb per second |
| D. | One coulomb each hour |
| Answer» D. One coulomb each hour | |
| 4190. |
As the diameter of a wire is doubled, the resistance becomes |
| A. | twice |
| B. | one half |
| C. | one fourth |
| D. | four times |
| Answer» D. four times | |
| 4191. |
Assertion (A): Two terminal black boxes of R and C can be identified by plotting their static V-I characteristics.Reason (R): The V-I characteristic of resistance is a straight line of slope R passing through origin. |
| A. | Both A and R are true and R is correct explanation of A |
| B. | Both A and R are true and R is not the correct explanation of A |
| C. | A is true but R is false |
| D. | A is false but R is true |
| Answer» E. | |
| 4192. |
A series resonant circuit has R = 10 &ohm;, L = 1 H and C = 1 mF. If R is increased to 20 &ohm; the resonant frequency |
| A. | increases |
| B. | decreases |
| C. | remains constant |
| D. | may increases or decreases |
| Answer» D. may increases or decreases | |
| 4193. |
In figure, VAB = |
| A. | 6 V |
| B. | 10 V |
| C. | 25 V |
| D. | 40 V |
| Answer» E. | |
| 4194. |
The Gaussian filter characteristic figure is realizable. |
| A. | True |
| B. | False |
| Answer» C. | |
| 4195. |
A coil of resistance R and inductance L is connected in series with 10 mF capacitor. The resonant frequency is 1000 Hz. Another 10 F capacitor is connected in parallel with the above capacitor. The new resonance frequency will be |
| A. | 1000 Hz |
| B. | more than 1000 Hz |
| C. | less than 1000 Hz |
| D. | may be more or less than 10000 Hz |
| Answer» D. may be more or less than 10000 Hz | |
| 4196. |
In an R-L-C series circuit, R = 2/L/C . If R is doubled |
| A. | the response will become underdamped |
| B. | the response will become overdamped |
| C. | the response will be critically damped |
| D. | the response may be under damped or overdamped |
| Answer» C. the response will be critically damped | |
| 4197. |
The circuit is figure, is in steady state with switch closed. At t = 0 switch is opened. The current i is |
| A. | <img src="/_files/images/electronics-and-communication-engineering/networks-analysis-and-synthesis/126-735-2.png"> |
| B. | <img src="/_files/images/electronics-and-communication-engineering/networks-analysis-and-synthesis/126-735-3.png"> |
| C. | <img src="/_files/images/electronics-and-communication-engineering/networks-analysis-and-synthesis/126-735-4.png"> |
| D. | <img src="/_files/images/electronics-and-communication-engineering/networks-analysis-and-synthesis/126-735-5.png"> |
| Answer» C. <img src="/_files/images/electronics-and-communication-engineering/networks-analysis-and-synthesis/126-735-4.png"> | |
| 4198. |
If V = 4 in the figure, the value of Is is given by |
| A. | 6 A |
| B. | 5/2 A |
| C. | 12 A |
| D. | none |
| Answer» B. 5/2 A | |
| 4199. |
In the circuit shown, the steady state is reached with S open S is closed at t = 0, the current I in the 1 &ohm; resistor connected is to be determined at t = 0+ is given by |
| A. | 1 |
| B. | 2 |
| C. | 3 |
| D. | 4/3 |
| Answer» B. 2 | |
| 4200. |
A current of 1 A in the coil of an iron cored electromagnet causes B = 0.5T. If current is 2A, B = |
| A. | 0.5 T |
| B. | 1 T |
| C. | 1 T or more |
| D. | 1 T or less |
| Answer» E. | |