Multiple choice question for engineering
Set 1
1. Demodulation is the process of _____________
a) Extraction of analog signal
b) Multiplication with carrier wave
c) Extraction of carrier wave
d) None of the mentioned
Answer
Answer: a [Reason:] Demodulation is the process of extraction of analog signal.
2. Discriminators are also known as _____________
a) Modulators
b) Demodulator
c) Converters
d) Incriminators
Answer
Answer: b [Reason:] Demodulators are also known as discriminators.
3. Which of the following act as slope detector?
a) FM detector
b) Tuned FM detector
c) AM detector
d) Tuned AM detector
Answer
Answer: b [Reason:] Tuned AM detector act as slope detector which detect slope of characteristic.
4. Which of the following circuit limit amplitude in FM signal?
a) Amplitude limiter
b) Amplitude controller
c) Amplitude magnifier
d) None of the mentioned
Answer
Answer: a [Reason:] Amplitude limiter circuit limit amplitude of FM signal.
5. Single tuned circuit is used for _______________
a) Narrow band operation
b) Wide band operation
c) Specific band operation
d) None of the mentioned
Answer
Answer: a [Reason:] Single tuned circuits are used for narrow band operation since it has very small linear frequency range.
6. Foster-seely detector is ___________
a) AM detector
b) FM detector
c) AM demodulator
d) None of the mentioned
Answer
Answer: b [Reason:] Foster-seely detector is Frequency Modulator detector.
7. Foster-seely detector is used for carrier frequency____________
a) Below 1 KHz
b) Below 1MHz
c) Above 1MHz
d) Above 5MHz
Answer
Answer: c [Reason:] Foster-seely detector is used where carrier wave has frequency greater than 1MHz.
8. PLL stands for _____________________
a) Phase loaded loop
b) Phase least loop
c) Phase locked loop
d) None of the mentioned
Answer
Answer: c [Reason:] PLL is the short form of Phase Locked Loop.
9. PLL is a ______________
a) Negative feedback system
b) Positive feedback system
c) Open loop system
d) None of the mentioned
Answer
Answer: a [Reason:] PLL is a negative feedback system with voltage controlled oscillator in feedback path.
10. Phase sensitive detector is used as _____________
a) Peak detector
b) Error detector
c) Threshold detector
d) Phase detector
Answer
Answer: b [Reason:] Phase sensitive detector is used as error detector.
Set 2
1. Typical conversion speed of ADC is _______________
a) Less than 1µs
b) Less than 100 µs
c) Less than 500 µs
d) Greater than 1000 µs
Answer
Answer: b [Reason:] Typical conversion speed of ADC is between 1µs and 100 µs.
2. Which of the following type output is provided by ADC?
a) Serial type
b) Parallel type
c) Both serial and parallel type
d) None of the mentioned
Answer
Answer: c [Reason:] ADC provides both serial and parallel type output according to application.
3. Which of the following method is employed for ADC?
a) Ladder network
b) Successive approximation type
c) PWM type
d) None of the mentioned
Answer
Answer: b [Reason:] In successive approximation method input value is constantly compared with a reference value.
4. Successive approximation is slow for large bit application.
a) True
b) False
Answer
Answer: b [Reason:] Successive approximation method is much faster in large bit application.
5. Which of the following represents range of frequency measured by ADC?
a) Bandwidth
b) Threshold frequency
c) Peak frequency
d) None of the mentioned
Answer
Answer: a [Reason:] Bandwidth of ADC is the maximum range of frequency measured by ADC.
6. Dynamic range of ADC is depended on_______________
a) Resolution
b) Linearity
c) Accuracy
d) All of the mentioned
Answer
Answer: d [Reason:] Dynamic range of ADC is depended on both resolution, linearity and accuracy.
7. Small timing errors in ADC additional to noise is known as ____________
a) Jitter
b) Aliasing
c) Super noise
d) None of the mentioned
Answer
Answer: a [Reason:] Jitter is a type of noise that is produced additional to noise.
8. ENOB in ADC stand for _________________
a) Effective number of bytes
b) Effective number of bits
c) Effective nibble baud
d) None of the mentioned
Answer
Answer: b [Reason:] Effective number of bits (ENOB) represents number of bits measured by ADC.
9. ENOB is negation of resolution.
a) True
b) False
Answer
Answer: b [Reason:] ENOB or effective number of bits is the number of bits measured by ADC and it is equal to resolution.
10. Rotary encoder is an ADC.
a) True
b) False
Answer
Answer: a [Reason:] Rotary encoder can be treated as an encoder which converts analog quantity to digital quantity.
Set 3
1. Indicating measurements are used for_______________
a) Static measurements
b) Dynamic masurements
c) Both static and dynamic measurements
d) None of the mentioned
Answer
Answer: a [Reason:] Indicating instruments are helpful in static measurements.
2. Indicating instruments can be used for measuring _____________
a) AC quantities
b) DC quantities
c) Both AC and DC
d) None of the mentioned
Answer
Answer: c [Reason:] Indicating instruments can be used for measuring both AC and DC quantities.
3. Which of the following have low loading effect?
a) Electronic system
b) Electrical system
c) Both have equal effect
d) None of the mentioned
Answer
Answer: a [Reason:] Electronic systems have low loading effect than electrical system.
4. Which of the following act as end devices in pneumatic system?
a) Bourden tubes
b) Mechanical gears
c) Electronic devices
d) All of the mentioned
Answer
Answer: a [Reason:] Due to the use of air pressure, bourden tubes are used as the end devices is pneumatic system.
5. Scale calibration of indicating instruments are always linear.
a) True
b) False
Answer
Answer: b [Reason:] Scale calibration may not be always linear and accuracy in reading becomes poorer in portions of scale where it is cramped.
6. Majority of indicators are _________________
a) Current operated devices
b) Voltage operated devices
c) Pressure operated devices
d) None of the mentinoned
Answer
Answer: a [Reason:] Most of the indicators are current-operated devices and they can be used for both AC and DC.
7. AC indicators are used at frequency__________________
a) Very low value of less than 1Hz
b) Less than 200Hz
c) Greater than 1KHz
d) Higher value of about 1MHz
Answer
Answer: b [Reason:] AC indicators are used for frequency less than 200 Hz.
8. PMMC devices in indicators create __________________
a) Stationary magnetic field
b) Rotating magnetic field
c) Electric field
d) None of the mentioned
Answer
Answer: a [Reason:] Permanent magnet moving coil instruments in indicators are used for creating stationary magnetic field.
9. Which of the following represents stationary part of PMMC device?
a) Coil
b) Control system
c) Magnetic system
d) None of the mentioned
Answer
Answer: c [Reason:] In PMMC devices, magnatic system remain as stationary part.
10. Which of the following represent function of spring in PMMC devcie?
a) Control system
b) Path for current in and out of coil
c) Both control and path for current
d) None of the mentioned
Answer
Answer: c [Reason:] Spring in PMMC devices act as both control system and path for current in and out of coil.
Set 4
1. AM signals are the _____________ of data signal and carrier signal.
a) Difference
b) Sum
c) Product
d) Ratio
Answer
Answer: c [Reason:] Amplitude modulated signals are the product of data signal and carrier signal.
2. Which of the following can produce AM signal?
a) Any electronic device
b) Any electronic device with linear chara
c) Any electronic device with non-linear chara
None of the mentioned
Answer
Answer: c [Reason:] Any electronic device with non-linear Vi and Io can be used to produce AM signals.
3. Balanced and double balanced modulators produce ________________
a) Amplitude modulated signal
b) Frequency modulated signal
c) Both AM and FM
d) None of the mentioned
Answer
Answer: a [Reason:] AM signal are produced by both balanced and double balanced modulators.
4. FM generators for communication has frequency ______________
a) Less than 10MHz
b) Between 10MHz and 100MHz
c) Between 100MHz and 300MHz
d) Above 500MHz
Answer
Answer: b [Reason:] FM generators for communication has frequency range between 10MHz and 100MHz.
5. Power level of FM signal in space telemetry and entertainment system are equal.
a) True
b) False
Answer
Answer: b [Reason:] Power level of FM signal in space telemetry is far lower than in entertainment system.
6. Indirect FM generators uses ____________
a) Crystal oscillator
b) Wien bridge oscillator
c) LC oscillator
d) RC tuned circuit
Answer
Answer: a [Reason:] Indirect FM generators uses crystal oscillators due to its higher frequency stability.
7. Amstrong modulator is _________________
a) Direct modulator
b) Indirect modulator
c) Unbalanced modulator
d) Balanced modulator
Answer
Answer: b [Reason:] Amstrong modulator is an indirect FM generator.
8. Modulation index is the product of Δfc and fm.
a) True
b) False
Answer
Answer: b [Reason:] Modulation index is the ratio of Δfc and fm.
9. Modulation index for music broadcasting ___________ with increasing frequency.
a) Increases
b) Decreases
c) Constant
d) None of the mentioned
Answer
Answer: b [Reason:] Modulation index for music broadcasting will decrease with increasing frequency.
10. Tank circuit contains _____________
a) Inductor
b) Capacitor
c) Both inductor and capacitor
d) None of the mentioned
Answer
Answer: c [Reason:] Tank circuit contains both inductor and capacitor.
Set 5
1. Pen recorders are used for signals with frequency ______________
a) Less than 0.1Hz
b) Less than 1Hz
c) Medium frequency
d) High as 1KHz
Answer
Answer: a [Reason:] Pen recorders are used for signals with very low frequency as less than 0.1Hz.
2. Which of the following device is used in low-level dc voltages?
a) PMMC recorders
b) Self-balancing potentiometers
c) Pen recorders
d) Circular recorders
Answer
Answer: b [Reason:] Self-balancing potentiometers are used for low level dc voltages.
3. Which of the following device can be used for concurrent measurement of two variables?
a) PMMC devices
b) Pen recorders
c) X-Y plotter
d) Circular recorder
Answer
Answer: c [Reason:] X-Y recorders are devices which can be used for measuring two variables concurrently.
4. CRT act as converter of _________________
a) Displacement to voltage
b) Voltage to displacement
c) Voltage to voltage converter
d) None of the mentioned
Answer
Answer: b [Reason:] CRT convert input voltage to displacement of electron beam.
5. Band width of CRT will be _____________
a) Up to 10 KHz
b) Up to 100 KHz
c) Up to 1 MHz
d) up to 10 MHz
Answer
Answer: d [Reason:] Bandwidth of CRT may vary up to 10 MHz.
6. Which of the following factors determine accuracy of CRT?
a) Size of screen
b) Gain of amplifier
c) Both size of screen and gain of amplifier
d) None of the mentioned
Answer
Answer: c [Reason:] Accuracy of CRT is determined by both size of screen and constancy of gain of amplifier used.
7. Transient recorder is a storage oscilloscope.
a) True
b) False
Answer
Answer: a [Reason:] Transient recorder is a type of storage recorder which can store data for a short duration.
8. Fibre optic oscilloscope is a ___________________
a) Single channel CRO
b) Dual channel CRO
c) Multi channel CRO
d) None of the mentioned
Answer
Answer: a [Reason:] Fibre optic oscilloscope is a single channel CRO.
9. Input impedance of oscilloscope is _______________
a) Low as below 1Hz
b) 1KHz
c) As high as 1MHz
d) None of the mentioned
Answer
Answer: c [Reason:] Input impedance of oscilloscope is as high as 1MHz.
10. CRO enable storage of data.
a) True
b) False
Answer
Answer: b [Reason:] Conventional oscilloscope doesn’t support storage of data.