MCQOPTIONS
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MCQOPTIONS
This section includes 100 Mcqs, each offering curated multiple-choice questions to sharpen your Graduate Aptitude Test (GATE) knowledge and support exam preparation. Choose a topic below to get started.
| 1. |
At room temperature the current in an intrinsic semiconductor is due to |
| A. | holes |
| B. | electrons |
| C. | ions |
| D. | holes and electrons |
| Answer» E. | |
| 2. |
A geosynchronous satellite |
| A. | has the same period a that of the Earth |
| B. | has a circular orbit |
| C. | rotates in the equatorial plane |
| D. | has all of the above |
| Answer» C. rotates in the equatorial plane | |
| 3. |
A transponder is a satellite equipment which |
| A. | receives a signal from Earth station and amplifies |
| B. | changes the frequency of the received signal |
| C. | retransmits the received signal |
| D. | does all of the above-mentioned functions |
| Answer» E. | |
| 4. |
The INTELSAT-IV satellite launched in 1974 had two earth coverage antenna and two narrower-angle antennas subtending 4.5°. The signal from narrow-angle antenna was stronger than that from earth- coverage antenna by a factor of |
| A. | 17.34/4.5 |
| B. | 17.34 x 4.5 |
| C. | (17.34/4.5)2 |
| D. | (17.34/4.5)4 |
| Answer» D. (17.34/4.5)4 | |
| 5. |
The angle subtended by earth at geostationary communication satellite is |
| A. | 17.34° |
| B. | 51.4° |
| C. | 120° |
| D. | 60° |
| Answer» B. 51.4° | |
| 6. |
The discussing sharing of a communication satellite by many geographically dispersed Earth station, DAMA means |
| A. | Demand-Assigned Multiple Access |
| B. | Decibel Attenuated Microwave Access |
| C. | Digital Analog Master Antenna |
| D. | Dynamically-Assigned Multiple Access |
| Answer» B. Decibel Attenuated Microwave Access | |
| 7. |
A 20 m antenna gives a certain uplink gain at frequencies of 4/6 GHz. For getting same gain in the 20/30 GHz band, antenna size required is metre. |
| A. | 100 |
| B. | 4 |
| C. | 1 |
| D. | 10 |
| Answer» C. 1 | |
| 8. |
Noise temperature of Sun is more than __________ °K. |
| A. | 1000 |
| B. | 5000 |
| C. | 100000 |
| D. | 500 |
| Answer» D. 500 | |
| 9. |
The present total cost per watt of power generation in geosynchronous orbit is nearly Rs. |
| A. | 20 |
| B. | 50 |
| C. | 100 |
| D. | 5 |
| Answer» B. 50 | |
| 10. |
Rotation of a geosynchronous satellite means its |
| A. | drift from stationary position |
| B. | wobbling |
| C. | three-axis stabilization |
| D. | three-dimensional stabilization |
| Answer» C. three-axis stabilization | |
| 11. |
The first geostationary satellite launched in 1965 was called |
| A. | ANIK |
| B. | EARLY BIRD (Intelsat-I) |
| C. | WESTAR |
| D. | MOLNIYA |
| Answer» C. WESTAR | |
| 12. |
Which are the popular IF frequencies for microwave and radar receivers operating on frequencies in the range 1 to 10 GHz |
| A. | 30, 60 and 70 kHz |
| B. | 3, 6 and 7 kHz |
| C. | 30, 60 and 70 MHz |
| D. | 3, 6 and 7 GHz |
| Answer» D. 3, 6 and 7 GHz | |
| 13. |
RF amplifiers are used in radio receivers for |
| A. | improved image frequency rejection |
| B. | improved rejection of adjacent unwanted signals |
| C. | prevention of re-radiation of the local oscillator through the antenna of the receiver |
| D. | all of the above |
| Answer» E. | |
| 14. |
A heterodyne frequency changer is called a |
| A. | Modulator |
| B. | Mixer |
| C. | Demodulator |
| D. | Frequency translator |
| Answer» C. Demodulator | |
| 15. |
A duplexer is a device used to |
| A. | feed more than one receiver from a single antenna |
| B. | connect two transmitters to the same antenna |
| C. | connect a receiver and a transmitter to the same antenna |
| D. | none of these |
| Answer» D. none of these | |
| 16. |
In a broadcast superheterodyne receiver |
| A. | the local oscillator operates below the signal frequency |
| B. | local oscillator frequency is normally double the IF |
| C. | RF amplifier normally works at kHz above the carrier frequency |
| D. | mixer input must be tuned to the signal frequency |
| Answer» E. | |
| 17. |
Most popular IF for receivers tuning to 540 to 1650 kHz is |
| A. | 433 kHz |
| B. | 455 kHz |
| C. | 545 kHz |
| D. | 555 kHz |
| Answer» C. 545 kHz | |
| 18. |
Which of the following should be used in order to prevent overloading or the last IF amplifier in a receiver? |
| A. | Variable selectivity |
| B. | Variable sensitivity |
| C. | Double conversion |
| D. | Squelch |
| Answer» C. Double conversion | |
| 19. |
The function of an AM detector circuit is to |
| A. | rectify the input signal |
| B. | discard the carrier |
| C. | provide audio signal |
| D. | all of the above |
| Answer» E. | |
| 20. |
In a superheterodyne receiver |
| A. | the IF stage has better selectivity than RF stage |
| B. | the RF stage has better selectivity than IF stage |
| C. | he RF stage has same selectivity than IF stage |
| D. | none of the above |
| Answer» B. the RF stage has better selectivity than IF stage | |
| 21. |
The noise generated by a resistor depends upon |
| A. | its resistance value |
| B. | its operating temperature |
| C. | both its resistance value and operating temperature |
| D. | none of the above |
| Answer» C. both its resistance value and operating temperature | |
| 22. |
The log magnitude curve for a constant gain K is a |
| A. | horizontal straight line |
| B. | horizontal straight line of magnitude 20 log K decibels |
| C. | an inclined line having slope K |
| D. | an inclined line having slope -K |
| Answer» C. an inclined line having slope K | |
| 23. |
For the transport lag G(jω) = e-jωT, the magnitude is always equal to |
| A. | 0 |
| B. | 1 |
| C. | 10 |
| D. | 0.5 |
| Answer» C. 10 | |
| 24. |
The phase margin and damping ratio have no relation. |
| A. | True |
| B. | False |
| Answer» C. | |
| 25. |
Assertion (A): The steady state response, of a stable, linear, time invariant system, to sinusoidal input depends on initial conditions. Reason (R): Frequency response, in steady state, is obtained by replacing s in the transfer function by jω |
| 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 correct but R is wrong |
| D. | R is correct but A is wrong |
| Answer» E. | |
| 26. |
Bellows converts |
| A. | pressure difference into displacement |
| B. | pressure difference into voltage |
| C. | displacement into pressure difference |
| D. | either (a) or (c) |
| Answer» B. pressure difference into voltage | |
| 27. |
A system has its two poles on the negative real axis and one pair of poles lies on jω axis. The system is |
| A. | stable |
| B. | unstable |
| C. | limitedly stable |
| D. | either (a) or (c) |
| Answer» D. either (a) or (c) | |
| 28. |
When a unit step voltage drives a lag network the output |
| A. | remains constant at unit step value |
| B. | increases exponentially from zero to final value |
| C. | decreases exponentially from 1 to 0 |
| D. | either (b) of (c) depending on values of R and C |
| Answer» C. decreases exponentially from 1 to 0 | |
| 29. |
From the noise point of view, bandwidth should |
| A. | be large |
| B. | not be too large |
| C. | should be as large as possible |
| D. | should be infinite |
| Answer» C. should be as large as possible | |
| 30. |
A stepper motor is |
| A. | a two phase induction motor |
| B. | is a kind of rotating amplifier |
| C. | is an electromagnetic transducer used to convert an angular position of shaft into electrical signal |
| D. | is an electromechanical device which actuates a train of step angular movements in response to a train of input pulses on one to one basis |
| Answer» E. | |
| 31. |
Assertion (A): Potentiometers can not be used as error detectors in position control systems. Reason (R): The resolution of a potentiometer places an upper limit on its accuracy |
| 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 correct but R is wrong |
| D. | R is correct but A is wrong |
| Answer» E. | |
| 32. |
If a system is to follow arbitrary inputs accurately the bandwidth should be |
| A. | large |
| B. | small |
| C. | very small |
| D. | neither small nor large |
| Answer» B. small | |
| 33. |
Whether a linear system is stable or unstable that it |
| A. | is a property of the system only |
| B. | depends on the input function only |
| C. | both (a) and (b) |
| D. | either (a) or (b) |
| Answer» B. depends on the input function only | |
| 34. |
Mechanical impedance is the ratio of |
| A. | rms force to rms velocity |
| B. | rms force to rms displacement |
| C. | rms velocity to rms displacement |
| D. | none of the above |
| Answer» B. rms force to rms displacement | |
| 35. |
The quiescent collector current IC, and collector to emitter voltage VCE in a CE connection are the values when |
| A. | ac signal is zero |
| B. | ac signal is low |
| C. | ac signal is negative |
| D. | either (a) or (b) |
| Answer» B. ac signal is low | |
| 36. |
An amplifier with loop gain Aβ will be more stable for value of Aβ as |
| A. | 0.95 |
| B. | 0.7 |
| C. | 1.2 |
| D. | 1.5 |
| Answer» C. 1.2 | |
| 37. |
A half wave diode rectifier has a capacitance input filter. If input voltage is Vm sin ωt, PIV is |
| A. | Vm |
| B. | 2 Vm |
| C. | 3 Vm |
| D. | 4 Vm |
| Answer» C. 3 Vm | |
| 38. |
DC amplifiers have a tendency to be unstable. |
| A. | True |
| B. | False |
| Answer» B. False | |
| 39. |
An exponential amplifier has diode in feedback path. |
| A. | True |
| B. | False |
| Answer» C. | |
| 40. |
In class C operation of an amplifier circuit, the collector current exists for |
| A. | 360° of input wave |
| B. | 180° of input wave |
| C. | more than 180° of input wave |
| D. | less than 180° of input wave |
| Answer» E. | |
| 41. |
A bridge rectifier circuit has input of 50 Hz frequency. The load resistance is RL and filter capacitance is C. For good output wave shape, the time constant RLC should be at least equal to |
| A. | 10 ms |
| B. | 20 ms |
| C. | 50 ms |
| D. | 100 ms |
| Answer» E. | |
| 42. |
A CB amplifier has re = 6 Ω, RL = 600 Ω and a = 0.98. The voltage gain is |
| A. | 100 |
| B. | 600 x 0.98 |
| C. | 98 |
| D. | 6 |
| Answer» D. 6 | |
| 43. |
A forward voltage of 9 V is applied to a diode in series with a 1 kΩ load resistor. The voltage across load resistor is zero. It indicates that |
| A. | diode is short circuited |
| B. | diode is open circuited |
| C. | resistor is open circuited |
| D. | diode is either short circuited or open circuited |
| Answer» C. resistor is open circuited | |
| 44. |
The self bias provides |
| A. | stable Q point |
| B. | large voltage gain |
| C. | high input impedance |
| D. | high base current |
| Answer» B. large voltage gain | |
| 45. |
Maximum efficiency of class B power amplifier is 50%. |
| A. | True |
| B. | False |
| Answer» C. | |
| 46. |
Negative feedback reduces noise originating at the amplifier input. |
| A. | True |
| B. | False |
| Answer» C. | |
| 47. |
Assertion (A): For large signal variations an amplifier circuit has to be analysed graphically Reason (R): The output characteristics of a transistor is nonlinear. |
| A. | Both A and R are correct and R is correct explanation for A |
| B. | Both A and R are correct but R is not correct explanation for A |
| C. | A is correct R is wrong |
| D. | A is wrong R is correct |
| Answer» B. Both A and R are correct but R is not correct explanation for A | |
| 48. |
Assertion (A): CE amplifier is the most widely used BJT amplifier Reason (R): CE amplifier has zero phase difference between input and output |
| A. | Both A and R are correct and R is correct explanation for A |
| B. | Both A and R are correct but R is not correct explanation for A |
| C. | A is correct R is wrong |
| D. | A is wrong R is correct |
| Answer» D. A is wrong R is correct | |
| 49. |
The efficiency of a full wave rectifier using centre tapped transformer is twice that in full wave bridge rectifier. |
| A. | True |
| B. | False |
| Answer» C. | |
| 50. |
An amplifier has a large ac input signal. The clipping occurs on both the peaks. The output voltage will be nearly a |
| A. | sine wave |
| B. | square wave |
| C. | triangular wave |
| D. | (a) or (c) |
| Answer» C. triangular wave | |