In amplitude modulation AM, if modulation index is more than 100% then: The wave gets distorted.
Description : An amplitude modulation performs the mathematical operation of (A) Division (B) multiplication (C) subtraction (D) addition
Last Answer : An amplitude modulation performs the mathematical operation of multiplication
Description : In amplitude modulation technique the unmodulated carrier is referred to as having ______. A. 100% modulation B. 0% modulation C. 50% modulated D. Over modulated
Last Answer : B. 0% modulation
Last Answer : In AM the amplitude of carrier components remains constant, while in FM it does not remain constant.
Description : An AM transmitter is rated 100W at 100% modulation. How much power required for the carrier? A. 33.33 W B. 66.66 W C. 83.33 W D. 100 W
Last Answer : B. 66.66 W
Description : 100% modulation in AM means a corresponding increase in total power by: A. 25% B. 75% C. 100% D. 50%
Last Answer : D. 50%
Description : In an AM transmitter with 100% modulation, the voltage of the final RF stage will be
Last Answer : approximately four times the DC supply voltage
Description : What is the full form of 'AM' regarding radio broadcasting? (1) Amplitude Movement (2) Anywhere Movement (3) Amplitude Matching (4) Amplitude Modulation
Last Answer : (4) Amplitude Modulation Explanation: AM broadcasting is the process of radio broadcasting using amplitude modulation. AM was the first method of impressing sound on a radio signal and is still ... frequency. It then amplifies changes in the signal voltage to drive a loudspeaker or earphones.
Description : If the percentage modulation of an AM amplifier is 88% and the modulating signal is 1 volt, the carrier has an amplitude of _______________. A. 1.14 volts B. 0.88 volt C. 1.88 volts D. 0.12 volt
Last Answer : A. 1.14 volts
Description : Three audio waves with 100,200 and 300 volts amplitude respectively, simultaneously modulate a 450 volts carrier. What is the total percent of modulation of the AM wave? A. 69 % B. 115.5 % C. 50% D. 83%
Last Answer : D. 83%
Description : What is the full form of ‘AM’ regarding radio broadcasting? (1) Amplitude Movement (2) Anywhere Movement (3) Amplitude Matching (4) Amplitude Modulation
Last Answer : Amplitude Modulation
Description : Which of the following statement is false? Modulation is used to: (1) Reduce the bandwidth used (2) Separate differing transmissions (3) Ensure that intelligence may be transmitted over long distances (4) Allow the use of practicable antennas
Last Answer : Which of the following statement is false? Modulation is used to: Reduce the bandwidth used
Description : For 100% modulation, total power is? a) same as the power of unmodulated signal b) twice as the power of unmodulated signal c) four times as the power of unmodulated signal d) one and half times as the power of unmodulated signal
Last Answer : Ans: D
Description : For 100% modulation, power in each sideband is ________ of that of carrier? a) 50% b) 70% c) 60% d) 25%
Description : A modulation which does not follow the sine wave pattern, it produces undesirable harmonics such as spurious emission A. 0% modulated B. Over-modulated C. Unmodulated D. 100% modulated
Last Answer : B. Over-modulated
Description : At 100% modulation, the sum fo the effective voltages in both sidebands is equal to ______% of the unmodulated carrier voltage. A. 50 B. 71 C. 100 D. 25
Last Answer : B. 71
Description : In modulation technique, which of the following is referred to audible pitch? A. Width B. Frequency C. Harmonic D. Amplitude
Last Answer : B. Frequency
Description : This is referred to a product of simultaneous frequency and amplitude modulation or a carrier frequency variation which produces unwanted distortion. A. Absorption modulation B. Simultaneous modulation C. Dynamic instability D. Series modulation
Last Answer : C. Dynamic instability
Description : Which of the following systems is not used in radio detection and ranging? A. Frequency shift B. Frequency modulation C. Pulse radar D. Amplitude modulation
Last Answer : D. Amplitude modulation
Description : Used for time division multiplexing. A. Frequency modulation B. Pulsed modulation C. SSB D. Amplitude modulation
Last Answer : B. Pulsed modulation
Description : Modulation means A. Varying of information B. Utilization of a single transmission channel to carry multiple signals C. Varying of some parameters of a carrier such as its amplitude to transmit information D. Transmit pulses in DC form on a copper wire
Last Answer : C. Varying of some parameters of a carrier such as its amplitude to transmit information
Description : ECE Board Exam March 1996 One type of pulse communications system uses pulse that appear as a group, and which vary in number according to the loudness of the voice. This type of ... A. pulse duration modulation B. pulse amplitude modulation C. pulse code modulation D. pulse position modulation
Last Answer : A. pulse duration modulation
Description : In frequency modulation, amplitude of modulated wave is A. positive B. negative C. constant D. zero
Last Answer : constant
Description : Variation in amplitude or frequency of carrier wave is called A. amplitude modulation B. frequency modulation C. modulation D. bandwidth
Last Answer : modulation
Description : Quadrature amplitude modulation(QAM) isa combination of ___________. A) ASK and FSK B) ASK and PSK C) PSK and FSK D) none of the above
Last Answer : ASK and PSK
Description : Bits can be sent over guided and unguided media as analog signal by ___________ a. digital modulation b. amplitude modulation c. frequency modulation d. phase modulation
Last Answer : a. digital modulation
Description : what is angle and amplitude modulation? what is noise in modulation?
Last Answer : Ans- modulation means change. to send a message of low frequency to a far distance we use a carrier of high frequency to carry the message. while transfering we change some parameters of ... is an unwanted signal which enter in signal while transfering a signal and makes the signal distorted.
Description : What, if any, noise susceptibility advantage exists for pulse-amplitude modulation over analog amplitude modulation?
Last Answer : Both are susceptible to noise and interference
Description : With a single modulating tone, what is the amplitude of the sideband frequencies at 100-percent modulation?
Last Answer : One-half the amplitude of the carrier.
Description : What is amplitude modulation?
Last Answer : Any method of modulating an electromagnetic carrier frequency by varying its amplitude in accordance with the intelligence.
Description : n digital modulation, it is similar to standard amplitude modulation except there is only two amplitudes possible.
Last Answer : amplitude shift keying
Description : A pulse modulation technique as the width of a constant amplitude pulse is varied proportional to the amplitude of the analog signal at the time the signal is sampled.
Last Answer : PWM, PLM, PDM
Description : Pulse – amplitude modulation signals are multiplexed by using
Last Answer : FET switches
Description : Describe amplitude shift keying (ASK) modulation with suitable circuit diagram.
Last Answer : Explanation:- ASK MODULATOR: The process where a binary information signal directly modulates the amplitude of an analog carrier. The digital signal is used to switch the carrier between amplitude levels is ... Block diagram of ASK Transmitter / ASK modulator:- Waveforms:-
Description : Amplitude modulation is used for broadcasting because (A) it is move noise immune than other modulation systems (B) compared with other systems it requires less transmitting power (C) ... receiver complexity (D) no other modulation system can provide the necessary bandwidth for high fidelity.
Last Answer : Amplitude modulation is used for broadcasting because its use avoids receiver complexity
Description : In amplitude modulation scheme, the over-modulation (A) is desired phenomenon (B) helps in signal recovery (C) is undesired phenomenon (D) Envelope of AM maintains the shape of the baseband signal
Last Answer : In amplitude modulation scheme, the over-modulation is desired phenomenon
Description : The antenna current is doubled when the modulation index is doubled in ______ AM system. A. A5C B. A3J C. A3 D. A3H
Last Answer : B. A3J
Description : If the modulation index of an AM wave is doubled, the antenna current is also doubled, the AM system being used is A. A5C B. A3J C. A3H D. A3
Description : Define modulation? State the desirable value of modulation index of AM.
Last Answer : Modulation: It is the process in which any of these Parameters (Amplitude, Frequency, Phase) of high frequency signal (carrier signal) are varied in accordance with low frequency signal(modulating signal) For an AM, modulation index range is 0 to 1.
Description : Give the expression for modulation index for AM and FM.
Last Answer : 1.Modulation index for AM ma=Vm / Vc Where Vm is modulating voltage Vc is the carrier voltage 2.Modulation index for FM mf=δ /fm where δ is the deviation fm is the modulating frequency
Description : Differentiate between AM and FM on the basis of: (i) Definition (ii) Bandwidth (iii) Modulation Index (iv) Application
Last Answer : Compare AM and FM on the basis of i)Definition ii)Bandwidth iii) Wave propogation iv)Number of sidebands
Description : Define modulation index in AM and give its formula.
Last Answer : In AM wave, the modulation index (m) is defined as the ratio of the amplitude of the modulating signal (Vm ) to the amplitude of carrier signal (Vc). m = Vm / Vc
Description : i) State the significance of modulation index in AM transmission. ii) Explain the effect of modulation index on AM wave with waveforms.
Last Answer : Significance of modulation index in AM transmission It is used to determine the strength and quality of transmitted signal. If the modulation index is small, then the amount of variation in ... amplitude part of its information is lost in the process of modulation which is undesirable.
Description : Compare AM with FM with respect to following points: a) Definition. b) Modulation index. c) Bandwidth. d) Side band.
Last Answer : Parameters AM FM Definition It is the process in which the amplitude of carrier signal is varied in accordance with the instantaneous value of modulating signal keeping frequency and ... frequency deviation. Side band There are two sidebands Infinite number of sideband
Description : If the radiated power of AM transmitter is 10 KW, the power in the carrier for modulation index of 0.6 is nearly: (1) 8.24 KW (2) 9.26 KW (3) 8.47 KW (4) 9.6 KW
Last Answer : If the radiated power of AM transmitter is 10 KW, the power in the carrier for modulation index of 0.6 is nearly: 8.47 KW.
Description : What is meant by the term modulation index? A. The processor index. B. The ratio between the deviation of a frequency modulated signal and the modulating frequency. C. The FM signal-to-noise ratio. D. The ratio of the maximum carrier frequency deviation to the highest audio modulating frequency.
Last Answer : B. The ratio between the deviation of a frequency modulated signal and the modulating frequency.
Description : Which determines the number of sideband components of FM? A. Modulation frequency B. Modulation index C. Carrier frequency D. All of these
Last Answer : B. Modulation index
Description : What is the difference between phase and frequency modulation? A. Is purely theoretical because they are the same in practice B. Lies in poorer audio response of phase modulation C. Lies in the different definitions of the modulation index D. Is too great to make two systems compatible
Last Answer : C. Lies in the different definitions of the modulation index
Description : Define modulation index in FM. What is maximum value of deviation ratio.
Last Answer : Modulation Index of FM: It is defined as the ratio of Frequency Deviation (δ) to the modulating signal frequency (fm). (OR)
Description : Compare narrow band FM with wide-band FM w.r.t. following points. (i) Modulation index (ii) Maximum deviation (iii)Range of modulating frequency (iv)Application
Last Answer : Sr. No Parameters Narrow band FM Wide band FM 1 Modulation index Less than or slightly greater than 1 Greater than 1 2 Maximum deviation ... like police wireless, ambulance etc. Entertainment broadcasting can be used for high quality music transmission
Description : Define modulation index of FM.
Last Answer : Modulation index of FM is defined as the ratio of the frequency deviation to the modulating frequency.