# What causes over modulation in am

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.

## Related questions

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

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

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

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

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

Answer : In amplitude modulation scheme, the over-modulation is desired phenomenon

Description : One advantage of AM over suppressed carrier AM is  A) Less power B) Less bandwidth C) Simpler detection D) Higher efficiency

Description : What is the full form of ‘AM’ regarding radio broadcasting? (1) Amplitude Movement (2) Anywhere Movement (3) Amplitude Matching (4) Amplitude Modulation

Description : Define modulation index in AM and give its formula.

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.

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 : 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

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

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

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

Description : Define modulation? State the desirable value of modulation index of AM.

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.

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

Answer : Compare AM and FM on the basis of i)Definition ii)Bandwidth iii) Wave propogation iv)Number of sidebands

Description : Compare AM with FM with respect to following points: a) Definition. b) Modulation index. c) Bandwidth. d) Side band.

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 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

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

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

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

Description :

Explain the significance of over modulation.

Description : Indicate which one of the following is NOT an advantage of FM over AM? (1) Better noise immunity is provided (2) Lower bandwidth is required (3) The transmitted power is more useful (4) Less modulating power is required

Answer : Indicate which one of the following is NOT an advantage of FM over AM? (1) Better noise immunity is provided (2) Lower bandwidth is required (3) The transmitted power is more useful (4) Less modulating power is required

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

Answer : They are less prone to interference

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

Description :

Answer : In AM wave, useful power is carried by Side bands

Description :

What causes diodes to fail in alternator?

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

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

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) its use avoids receiver complexity (D) no other modulation system can provide the necessary bandwidth for high fidelity.

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

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

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

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

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

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

Description :

Answer : Frequency modulation gives Less noise

Description :  For identical total transmitted power, the ratio of S/N for wide band FM to S/N of DSB-AM (with ma=1) is : ( Given fm = 15 KHz & frequency. deviation =+/- 75 KHz) a. 112.5 b. 300 c. 75 d. 450

Description : AM transmitter operating below about 5 MHz usually make use of  A) Marconi antenna B) Turnstile antenna C) Hertz dipole D) Folded dipole

Description : What do you mean by active filter? State its advantages over passive filter . Define pass band & stop band with respect to filter.

Answer : Active Filter: Active Filter is formed by using active element along with the passive components.  Advantages of Active filter over Passive filter: High value of pass band gain can be obtained. It is ... pass band.  Stop Band Filter: The frequency range which is attenuated is known as stop band.

Description :

Answer : VLSI is small and consume less power and its designing is easy.

Description :

Answer : The skin effect causes current to flow Near the surface of the conductor

Description :

Description : As per Shannon’s channel capacity theorem, if samples are transmitted in ‘T’ seconds over a noisy channel which is bandlimited to ‘B’ Hz. The number of samples ‘n’ is given by (symbols/notations carry their usual meaning) A) B/T B) T/B C) 2BT D) BT/2

Answer : As per Shannon’s channel capacity theorem, if samples are transmitted in ‘T’ seconds over a noisy channel which is bandlimited to ‘B’ Hz. The number of samples ‘n’ is given by ( ... /notations carry their usual meaning) A) B/T B) T/B C) 2BT D) BT/2

Description : Why silicon is preferred over Ge?

Answer : 1) Silicon is plenty available compared to Ge. 2) Extraction process of Si is easy and less expensive. 3) Si has more thermal stability as compared to Ge. 4) Si has more breakdown voltage as compared to Ge.

Description : Define modulation index in FM. What is maximum value of deviation ratio.

Answer : Modulation Index of FM: It is defined as the ratio of Frequency Deviation (δ) to the modulating signal frequency (fm). (OR)

Description : What is found in frequency modulation ? (1) Fixed frequency (2) Fixed dimension (3) Change in frequency and dimension (4) Change in dimension only

Description : What is channel length modulation in MOSFET?

Answer : Shortening of lenght of the inverted channel region with increase in drain bias for large drain biases due to which current increases with drain bias and output resistance decreases is called channel length modulation in MOSFET.

Description : The element I am thinking about has several interesting characteristics. It occupies the same column in the periodic table as lead. Resistors which are commonly found in electronic circuits are often made out of this element. In addition, in one of its forms, this element is one of the hardest substances on earth. What element am I thinking about?

Description : "General Sherman" is my name. In 1972 I had a spread of 90 feet and a height of 272 feet. What am I and in what national park do I live?

Answer : ANSWER: GIANT SEQUOIA (accept: SIERRA REDWOOD or BIG TREE) in SEQUOIA NATIONAL PARK

Description : "The winners in life think constantly in terms of I can, I will, and I am. Losers, on the other hand, concentrate their waking thoughts on what they should have or would have done, or what they can't do." - Dennis Waitley

Description : What is the maximum data rate that can be transmitted using a QPSK modulation with a roll-off factor of 0.2 for a 36 MHZ transponder?  A) 7.2 Mbps B) 30 Mbps C) 43.2 Mbps D) 60 Mbps

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Answer : PWM means the width of pulse signal can be varied by varying ton & tOFF.

Description : What is a typical wavelength of an AM radio wave? w) 3000 meters x) 300 meters y) 30 meters z) 3 meters