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%

1 Answer

Answer :

D. 83%

Related questions

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 : A 1 Mhz carrier is amplitude modulated by a pure 200-Hz audio test tone. Which of the following combinations of frequencies represent the total content of the AM signal? A. 1 MHz and 200 Hz B. 1 MHz and 1000.2 kHz C. 999.8 kHz, 1000 kHz, and 1000.2 kHz D. 999.8 kHz and 1000.2 kHz

Last Answer : C. 999.8 kHz, 1000 kHz, and 1000.2 kHz

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

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 : 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 : 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

Description : A 1000W carrier is amplitude modulated to a depth of 85%. Calculate the total power of the modulated wave? A. 1361.25 W B. 680.62 W C. 1425 W D. 712.5 W

Last Answer : A. 1361.25 W

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 : What is meant by the term deviation ratio? A. The ratio of the carrier center frequency to the audio modulating frequency B. The ratio of the highest audio modulating frequency to the ... audio modulation frequency D. The ratio of the audio modulating frequency to the center carrier frequency

Last Answer : C. The ratio of the maximum carrier frequency deviation to the highest audio modulation frequency

Description : Which of the following is not a baseband signal modulation? A. RF carrier B. Video System C. Audio signal D. Binary coded pulses

Last Answer : A. RF carrier

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 : Variation in amplitude or frequency of carrier wave is called A. amplitude modulation B. frequency modulation C. modulation D. bandwidth

Last Answer : modulation

Description : Modulation in which the modulated wave is always present. A. Carrier modulation B. Front-end C. Continuous modulation D. Log-periodic modulation

Last Answer : C. Continuous modulation

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 : Two taps P and Q can separately fill a tank in 120mins and 150 mins respectively. There is a 3rd tap in the bottom of the tank to empty it. If all of the 3 taps are simultaneously opened, then the tank is full ... . In how much time the 3rd pipe alone can empty the tank? A) 100 B) 200 C) 300 D) 400

Last Answer : B Work done by the 3 tap in 1 min = 1/100 – ( 1/120 + 1/150) = 1/100 – (5+4/600) =1/100 – 9/600 =6-9/600 = - 3/600 = - 1/200(negative signs mean empting) Therefore the 3rd tap alone can empty the tank in 200 mins

Description : Two sources of light are said to be coherent if __________. A. they produce waves of the same wave length B. they have the same amplitude of vibration C. they produce waves in the medium simultaneously D. they produce waves of the same amplitude

Last Answer : D. they produce waves of the same amplitude

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 : The ratio of the monthly salaries of A and B is in the ratio 15 : 16 and that of B and C is in the ratio 17 : 18. Find the monthly income of C if the total of their monthly salary is Rs 1,87,450. A) Rs 66,240 B) Rs 72,100 C) Rs 62,200 D) Rs 65,800 E) Rs 60,300

Last Answer : Answer: A A/B = 15/16 and B/C = 17*18 So A : B : C = 15*17 : 16*17 : 16*18 = 255 : 272 : 288 So C’s salary = [288/(255+272+288)] * 1,87,450= Rs 66,240

Description : What is the maximum shear stress induced in a solid shaft of 50 mm diameter which is subjected to both bending moment and torque of 300 kN.mm and 200 kN.mm respectively? a. 9.11 N/mm2 b. 14.69 N/mm2 c. 16.22 N/mm2 d. 20.98 N/mm2

Last Answer : b. 14.69 N/mm2

Description : A 400 W carrier is amplitude modulated to a depth of 75%.Calculate the total power in AM wave. (i) Explain the types of noise in a communication system. (ii) Compare simplex and duplex mode of communication.

Last Answer : (i) Noise: Noise is any spurious or undesired disturbances that mask the received signal in a communication system. a) Atmospheric Noise: Atmospheric Noise is also known as static noise which is the ... remote control ExamplesWalkytalky,telephone,mobile,Radar, FAX,Pager 4

Description : A three-phase alternator is developing 300 amps, with a 0.8 power factor, at 450 volts. The true indicated power on the kilowatt meter, located on the main switchboard, will be ____________. A. 133 kw B. 155 kw C. 187 kw D. 212 kw

Last Answer : Answer: C

Description : A three-phase alternator is operating at 450 volts with the switchboard ammeter indicating 300 amps. The kw meter currently indicates 163.6 KW, with a power factor of 0.7. If the power factor increases to 0.8, the KW meter would then read ____________. A. 181.4 KW B. 186.8 KW C. 194.2 KW D. 201.4 KW

Last Answer : Answer: B

Description : A three-phase alternator is operating at 450 volts with the switchboard ammeter indicating 300 amps. The kw meter currently indicates 163.6 KW, with a power factor of 0.7. If the power factor increases to 0.8, the KW meter reading would increase by ___ A. 17.8 KW B. 23.2 KW C. 30.6 KW D. 37.8 KW

Last Answer : Answer: B

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 the effective radiated power of a repeater with 50 watts transmitter power output, 5 dB feedline loss, 4 dB duplexer and circulator loss, and 7 dB antenna gain? A. 300 W B. 315 W C. 31.5 W D. 69.9 W

Last Answer : C. 31.5 W

Description : In 2000-2001 the use of mechanical & electrical increased from a)20% to 45%. c) 45% to 75% b) 45 to below 83% d)40% to over 83 %

Last Answer : 40% to over 83 %

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 : 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 : 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 : How wide is the spectrum bandwidth of a single GSM carrier? A. 100 kHz B. 200 kHz C. 50 kHz D. 16 kHz

Last Answer : B. 200 kHz

Description : Optimum reaction temperature in steam reforming of naphtha is __________ °C. (A) 700 - 1000 (B) 300 - 450 (C) 1500-1700 (D) 100-200

Last Answer : (A) 700 - 1000

Description : What is the range of tempering temperature (°C) for most of the materials? (A) 75-100 (B) 200-300 (C) 350-450 (D) 500-600

Last Answer : (B) 200-300

Description : What is the range of the visible light cure beam: A. 100-120 nm B. 200-300 nm C. 400-430 nm D. 470 nm or 450-500 nm

Last Answer : D. 470 nm or 450-500 nm

Description : What is the term used to describe a spread spectrum communications system where the center frequency if a conventional carrier is altered many time per second in accordance with a pseudo ... hopping B. Direct sequence C. Time-domain frequency modulation D. Frequency compandored spread spectrum

Last Answer : A. Frequency hopping

Description : In radio regulation, the first symbol in the designation of radio emission is ______. A. Bandwidth B. Nature of signal(s) modulation the main carrier C. Type of modulation of the main carrier D. Type of information to be transmitted

Last Answer : C. Type of modulation of the main carrier

Description : It is an average power of a radio transmitter supplied to the antenna transmission line taken during a long sufficient interval of time and compared with the lowest frequency encountered in the modulation ... operating conditions. A. Carrier power B. Rated power C. Mean power D. Peak envelop power

Last Answer : C. Mean power

Description : Referred to as an average power from the radio transmitter supplied to the antenna transmission line taken during one radio frequency cycle under no modulation. A. Carrier power B. Rated power C. Peak envelop power D. Mean power

Last Answer : A. Carrier power

Description : Average power of a radio transmitter supplied to the antenna transmission line by a transmitter during one radio frequency cycle taken under the condition of no modulation. A. Peak envelop power B. Rated power C. Carrier power D. Mean power

Last Answer : C. Carrier power

Description : The third symbol in the designation of radio emission under the ITU rules refers to A. Type of the modulation of the main carrier B. Bandwidth C. Nature of the signals modulating the main carrier D. Type of information to be transmitted

Last Answer : D. Type of information to be transmitted

Description : The first symbol in the designation of radio emission under the ITU rules to A. Nature of signals modulating the main carrier B. Type of information to be transmitted C. Bandwidth D. Type of modulation of the main carrier

Last Answer : D. Type of modulation of the main carrier

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 : The carrier swing necessary to provide 80% modulation in the FM broadcasting band is __________. A. 150 kHz B. 120 kHz C. 60 kHz D. 75 kHz

Last Answer : B. 120 kHz

Description : ECE Board Exam March 1996 The letter-number designation B8E is a form of modulation also known as ___________. A. pilot carrier system B. independent sideband emission C. lincomplex D. vestigial sideband transmission

Last Answer : B. independent sideband emission

Description : For 100% modulation, power in each sideband is ________ of that of carrier? a) 50% b) 70% c) 60% d) 25%

Last Answer : Ans: D

Description : The ratio of the level of the modulated output of a transmitter under conditions of standard test modulation to the level of the demodulated output with no modulation applied both measured with the ... . Reference audio output B. None of these C. Audio frequency response D. Residual noise level

Last Answer : D. Residual noise level

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 : What is the first symbol of a radio signal transmission having an amplitude modulated signal carrier, double side band? A. C B. B C. H D. A

Last Answer : D. A

Description : Refers to the first symbol in an emission designation with an amplitude modulated main carrier represented by letter H. A. Single sideband suppressed carrier B. Double sideband full carrier C. Independent sideband D. Double sideband

Last Answer : B. Double sideband full carrier

Description : A carrier signal has ______. A. Constant peak amplitude B. The information C. Frequency range 20-20000 Hz D. A varying amplitude

Last Answer : A. Constant peak amplitude