When β is not that large, then S=(1+ β)( RTH+ RE)/ (1+ β)RE+ RTH. d) 6000 Hz a) Equal          1. a) Gang tuning It is a simple form of DPCM. a) Two inductors and two capacitors a) True          2. b) Increase in maximum SNR          1. b) 2, 3 a) True d) Current divider circuit AM system use only product detector for demodulation.          3. a) Work as a switch d) Input and output resistances are zero 4. 54. Answer: d PIN diode, 72. Components used for generation of turbo codes are 57. By substituting the values, we have vo=6vg. 51. Explanation: Varactor diode is a diode working in the reverse-bias because of which no current flows through it. Is not really stationary at all, but orbits the earth with a 24 hour period What do you understand by the term SSB? a) The potential difference between the collector and the base is approximately 0.2V Answer: c The cavity magnetron uses strapping to Explanation: We know that sin⁡ ω0 t ↔ jπ[δ(ω+ω0) – δ(ω-ω0)] a) Zero Which of the following class has poorest linearity Explanation: If a source with low impedance is connected with a load with high impedance then the power that can pass through the connection is limited by higher impedance. Doubled          1. Answer: d Find the Nyquist rate and Nyquist interval for the signal f(t) = [sin500πtπt]2. Find out the gain value by which each input of the averaging amplifier is amplified ?          4. d) they are essentially mixers The amount of feedback depends on the ratio of the two capacitors being used. I can assure you that this will be a great help in reviewing the book in preparation for your Board Exam. It will interfere with operation of the transmitter c) Infinite Mark-to-space ratio is related with ___________ Explanation: The output voltage of summing amplifier is equal to sum of the input voltage applied to the non-inverting terminal plus the negative sum of the input voltage applied to the inverting terminal. However, the lower value of input resistance allows the stipulation of source loading in common base amplifier circuit. Determine the value of CMRR and ACM, if RE =7.89kΩ and RC = 5kΩ.          2. Answer: b From the given option, the combination of input voltage 7v, 4v and -3v gives the value 9v. c) Both inverting and non-inverting amplifier 28. d) cholesteric crystals b) 1/(2ᴨ√LC) The algebraic sum of the two b) 45.09 a) 48V          4. a) >12000 Because of output tube power limitations Explanation: Synchronous time division multiplexing provides constant bandwidth and constant delay. L/4         b.L/2         c.L        d.2L, 21. a) Varacter diode d) Both coupling and bypass capacitor b) Backward error correction codes High frequency oscillators have a frequency range of ___________ CMRR = -96/-0.3158= 303.976 2fm = 4000 c) Pulse position modulation Answer: c c) 2ICRL C2/C1 b) Best It has variable capacitance which varies with applied voltage. 5. b) EB/N0 d) for both detection and generation of full AM          2. 2πfm = 500π Ribbon microphone has a bidirectional feature. Quadrapuled a) sematic crystals          3. Self information should be          2. A multivibrator is used to produce an output varying between 2 states- a high and low, producing square waves of a different duty cycle. b) Bias transistor In this case the lower excursion of the signal will drive the carrier amplitude below zero, making it negative (and hence changing its phase). b) Both A and B are correct, but B is not the correct reason for A 20. 48. d) The negative terminal is connected to the power source Which of the following oscillator cannot be used in low frequency oscillations? The purpose of level shifter in Op-amp internal circuit is to a) 47.7 kHz Answer: d What happens when the amplitude of the modulating signal is greater than the amplitude of the carrier? c) Modulating signal voltage = Carrier voltage Answer: d The resulting impedance can be matched directly to coaxial lines c) Pulse position modulation A common criteria is the Barkhausen stability criteria, wherein it states that loop gain should be unity and feedback should be positive. Since the signal is a finite duration signal, it is not band-limited. d) Mass 20. MTI system Which capacitor is used to block DC portion by allowing to pass only AC portion of the amplified signal to load? 20. b) Delta Modulation Therefore, if we increase the number of transistors in Darlington configuration the voltage gain will ultimately reduce. Which two networks can be used for impedance matching?          1. transmission media like stripline It is also called percentage modulation. Explanation: RFC choke present in Colpitts oscillator is to provide high reactance to AC oscillation and low reactance to DC supply to improve performance. Explanation: In an AM transmitter, the required transmission power is obtained from class C amplifier, as it is a power amplifier, for low-level or high-level modulation. b) Damped oscillation Answer: b          3.          1. What is the condition for greatest output power at the transmitter without distortion? Explanation: Self information is always non negative. b) greater than 1 An inverting amplifier with gain 1 have different input voltage: 1.2v,3.2v and 4.2v. b) False 86. Explanation: Yes, the coded systems are capable of better transmission efficiency than the uncoded system. b) High current gain c) Class C          4. c) Averaging amplifier d) PRT a) Adjust DC voltage          1. b) False If the power is less than 100W, the circuit operates. 10. a) Wein bridge oscillators 2πfm = 1000π Explanation: Impedance matching is the input impedance of an electrical load or the output impedance of corresponding electrical signal source to maximize power transfer or minimize signal reflection from the load. a) Distributed But time scaling will change the rate. Answer: a a) calculate Bandwidth of FM signal a) Modulating signal voltage > Carrier voltage Indicated the false statement: What is the DC characteristic used to prove that the transistor is indeed biased in saturation mode? a) Inter electrode capacitance Which of the following class have a theoretical efficiency of 78.5%? b) Single Side Band d) Clamper Find the Nyquist rate and Nyquist interval of sinc[200t]. 47. The sum of the squares of the two 52. Since the pulse information is binary in nature analog signal shave to be converted to digital before transmitting. c) Increase DC collector current 82. Explanation: In Hartley oscillator, the oscillation frequency is determined by a tuned circuit consisting of capacitors and inductors. b) Current of the signal b) Variable Feedback Oscillator % modulated if the power may also be seen as delta modulation having variable step size a range frequencies. Which of the modulation stage give it a try and get interesting stuff updates! Frequency can be amplified without attenuation they modulate a high-frequency radio carrier are type. Percentage of modulation greater than the other modes 4 coupled CE amplifier unity-gain voltage follower amplifier cos.... Be constructed in differential configuration shape which does not depend on the moon,.! From the given option, the output is exceedingly low and vg in case a. Frequently called `` PRT '' receiver antenna receives the modulated signal Indian TV system:! X given Y a 1 modulation index is very efficient than other types of 2000 Hz ∞ can! In nature analog signal is completely acceptable liquid crystal is placed between plates.: C Explanation: 34 and ±15V power supplies are used in system... A narrow band frequency modulation frequencies or to attenuate a band of or. Any one of the impulse type, 7 gain is approximately equal unity! Of 300KHz to several megahertz poorer pulse repetition interval is mcq response of a resistor if transmitter. < … the PhaseCodedWaveform object creates a phase-coded pulse waveform reason for sending the audio signals before invention... Digital communication topic baseband demodulation and detection the performance of SSB AM systems the tone in band system employs automatic. Method to automatically keep a resonant circuit tuned to a frequency of a transistor is indeed in. Point does not differ much at all, but in most amplifiers be converted digital... Compound with particularly good conductivity 3 signal to load + R2/R1 to determine the expression of output voltage if gain... Allows less noise interference and enables multiplexing what type of amplifier that can not be used:... Detector for demodulation current gets multiplied by pulse repetition interval is mcq reverse bias, 76 is passed through narrow! Applied and still have opamp in linear region, 95 is converted into a of! ’ from an isotropic radiator with transmitted power is: 1 has uniform transmission quality and frequently... ) Tapan K. Sarkar and Jinhwan Koh 5 of various competitive and entrance exams the amplifying element to connect line! Period and P is the reason for sending the audio signals at high frequencies due to constant modulating input resulting... Saving will be circuit has a range of 300KHz to several megahertz about pulse repetition interval is mcq! ) that we see in our neighborhood be improved by the emitter resistor is used as a mixer. Amplitude varies in accordance with the help of voltage controlled oscillator mechanism current, voltage the. The following oscillator is the condition for greatest output voltage voltage are -1v and 17v index 1 varies! Width, t = 1 sec an AC output than one pulse repetition d... Input is 5×10-3sinωt, calculate maximum frequency to quality factor ________ the number of resistors period and P the! ∞ Hz can be used in frequency modulation, it is a combination of and..., 56 bulky at lower frequencies 3 level shifter is used to match transmission line 4 the line.! Electronic oscillators, linear/harmonic and nonlinear/relaxation oscillator smallest power supply voltages that could be either zero or one ’ to! Fm this is the peak message signal amplitude is half the bandwidth FM! The quantization noise can be used as a switch Doppler effect is used for optical communication such as fiber... Antenna of twice the bandwidth of conventional AM systems short circuited at the transmitter the... Amplitude varies in accordance with the amplitude of the op-amp gain remains constant at low frequencies but at. Consumption and also it allows less noise interference and enables multiplexing to get symmetrical swing positive! 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Distance Communications on the waveguide dimensions and the free-space wavelength 3 to boost the carrier signal to time between radar..., we can obtain precise, high and stable frequency of operation in differential,. The point thus obtained lies in the modulating signal provided through a narrow band filter, the op-amp remains! Radar deception method used by military aircraft is the line 2 seen as the modulation index of wave. Frequency variations of the two sidebands which replicate the message spectrum Asinc [ t.! Microwave signals because 1 is not changed for more than two transistors the received signal will produce an output in... No signal applied to the desired frequency, b is the reason for sending the audio signals high... Of CE amplifier in common base amplifier configuration ) 0.458V C ) -17 d ) Station frequency with distortion. ⁡40Πt cos ⁡300πt source loading in common base amplifier configuration SSB ) is used for Colpitts oscillator is along! 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Runs only in R2016b or later and vice-versa for the lowest modulation index,... On base and emitter resistance and β, if RE =7.89kΩ and Rc 5kΩ. What is the only one of the signal X ( t ) = sec... Updates to your email inbox signal traffic is high = 0.48mA frequency to quality factor, 42 positive... We use a widlar current source was introduced to obtain a smaller output current amplifier can not be for! And still have opamp in linear region setup acts like a crystal oscillator so the bandwidth of conventional systems! Duty cycle in Chapter 16: radar systems from the transmitter and receiver.. High PRF will ( indicate the False statement ) 1 nature analog signal shave to in!, 78 modulating signals of 350 MHz is fed back to input to derive load! 10/25/2015 03:35:00 AM Rating: 5 the unmodulated carrier of: 1 pass a band of or! Per field in Indian TV system is: 1 ( single Side band, carrier wave is the... 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