79 views

1 Answer

Answer :

Excessive high voice signal may cause overmodulation.

Modulating component greater than carrier may cause overmodulation.

Setting the gain of the microphone too high may cause overmodulation.
Like 0 like

Please log in or register to answer this question.

Related questions

343 views

Description : The total power of an AM transmitter having a carrier power of 50 W and the percentage of modulation at 80% is A) 50 W B) 66 W C) 68 W D) 70 W 

Last Answer : The total power of an AM transmitter having a carrier power of 50 W and the percentage of modulation at 80% is 66 W

1 answer
289 views

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.

1 answer
79 views

Description : If modulation index is 0.6, maximum power efficiency (in %) of AM is about  A) 60 B) 30 C) 20 D) 10

0 answers
59 views

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

1 answer
543 views

Description : An FM signal with modulation index mƒ is passed through a frequency tripler. The modulation index of the output signal will be (1) mƒ (2) 3mƒ (3) 9mƒ (4) 27mƒ

Last Answer : An FM signal with modulation index mƒ is passed through a frequency tripler. The modulation index of the output signal will be 3mƒ

1 answer
73 views

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 

1 answer
80 views

Description :  The information rate to be transmitted is 900 bits /sec, FEC is 3/4 , the symbol rate for QPSK modulation scheme is : a. 225 symbols /sec b. 450 symbols /sec c. 600 symbols /sec d. 675 symbols /sec

0 answers
83 views

Description : The maximum transmission power efficiency of DSB-C Amplitude modulation is : a. 25% b. 33.33% c. 50% d. 100%

0 answers
109 views

Description : The modulation system inherently most noise resistant is:  (1) Frequency modulation (2) Pulse width modulation (3) Pulse code modulation (4) Phase modulation

Last Answer : The modulation system inherently most noise resistant is: Pulse code modulation.

1 answer
200 views

Description : Which one of the following statements is correct? Digital modulation techniques are used in satellite communication systems since:  (1) They are easier to handle (2) Large bandwidth utilization is possible (3) They have a higher spectral efficiency (4) They are less prone to interference

Last Answer : They are less prone to interference 

1 answer
154 views

Description : The modulation normally used with the digital data is  a. PM  b. AM  c. SSB  d. QPSK

0 answers
110 views

Description : In satellite communication, frequency modulation is used because satellite channel has  a. High modulation index  b. Small bandwidth and negligible noise  c. Large bandwidth and severe noise   d. Maximum bandwidth and minimum noise

0 answers
96 views

Description : A carrier signal of 600 V rms with 75% amplitude modulation is applied to 75 ohm antenna. The total side band power (in watts) is  A) 4800 B) 450 C) 950 D) 1350 

0 answers
52 views

Last Answer : Frequency modulation gives Less noise

1 answer
5 views

Description : Which cavity of a three-cavity klystron causes most of the velocity modulation?

Last Answer : The middle cavity.

1 answer
0 views

Description : Amplitude Modulation (AM).

0 answers
1 view

Description : An AM wave is represented by cm (t) = 6 (1+0.5 cos 12560 t) cos 22 x 105 t. Calcualte (i) amplitude and frequency of carrier. (ii) frequency of the modulating signal. (iii) modulation index. (iv) maximum and minimum amplitude of the AM wave.

0 answers
0 views

Description : A carrier wave c(t) = Acsin(ωct) is amplitude modulated by a message signal m(t) = Amsin(ωct) where Am = 10 v. The AM wave has a modulation index of 0.5 and side bands of frequencies 1010 kHz and 990 kHz. The value of ... (2) 5V; 2 MHz and 10 kHz (3) 20V; 1 MHz and 10 kHz (4) 20V; 2 MHz and 20 kHz

0 answers
1 view

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.

1 answer
3 views

Description : What modulation is normally used with digital data? A. AM B. FM C. SSB D. QPSK

Last Answer : D. QPSK

1 answer
2 views

Description : What type of modulation is used on voice and video signals? A. AM B. FM C. SSB D. QPSK

Last Answer : B. FM

1 answer
6 views

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

1 answer
54 views

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

1 answer
2 views

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

Last Answer : B. A3J

1 answer
2 views

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%

1 answer
3 views

Description : Both frequency and phase modulation utilize ________ modulation A. Phase B. AM and FM C. Digital D. Angle

Last Answer : D. Angle

1 answer
5 views

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

1 answer
15 views

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%

1 answer
38 views

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

1 answer
22 views

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.

1 answer
17 views

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

1 answer
32 views

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

2 answers
33 views

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

1 answer
27 views

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

1 answer
374 views

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.

1 answer
120 views

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

1 answer
342 views

Description : In amplitude modulation AM, if modulation index is more than 100% then: (1) Power of the wave increases. (2) Efficiency of transmission increases. (3) The wave gets distorted. (4) Bandwidth increases

Last Answer : In amplitude modulation AM, if modulation index is more than 100% then: The wave gets distorted.

1 answer
88 views

Description : The amplifiers following the modulated stage in a low level modulation AM system be  (A) linear amplifier (B) harmonic generators (C) class C power amplifiers (D) class untuned amplifiers

Last Answer : The amplifiers following the modulated stage in a low level modulation AM system be class C power amplifiers

1 answer
401 views

Description : If the carrier of a 100 percent modulation modulated AM wave is suppressed, the percentage power saving will be (A) 50.55 (B) 15.55 (C) 10.66 (D) 66.66

Last Answer : If the carrier of a 100 percent modulation modulated AM wave is suppressed, the percentage power saving will be 66.66

1 answer
141 views

Description :  AM transmitter has a carrier power of 30 W. The percentage of modulation is 85%. Calculate the total power : (A) 5.4 W (B) 40.8 W (C) 10.8 W (D) 20.4 W

0 answers
3 views

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

1 answer
4 views

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

1 answer
27 views

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

1 answer
9 views

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

1 answer
3 views

Description : A modulation technique where data rates in excess of 56 kbps can be achieved over telephone circuits

Last Answer : Trellis Code Modulation

1 answer
56 views

Description : Which modulation scheme would you suggest for high speed data transmission over a fading channel?  A) MSK B) BPSK C) FSK D) OFDM

0 answers
...