Define the term signal to noise ratio. 

1 Answer

Answer :

Signal to Noise ratio: The ratio of the strength of an electrical or other signal carrying information to that of unwanted interference is called as signal to noise ratio.

OR

Signal to Noise Ratio is defined as the ratio of signal power to the noise power at the same point.

S/N=Ps/Pn

where,Ps=Signal Power

Pn=Noise Power at the same point

Related questions

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 : Sketch AM signal in (1)Time domain (2)Frequency domain.

Last Answer : AM in Time domain AM in frequency domain

Description : Draw the block diagram of AM. Super heterodyne ratio receiver and state the function of each block

Last Answer : AM super heterodyne receiver works on the principle of super heterodyning. In the super heterodyne receiver, the incoming signal voltage is combined with a Signal generated in the receiver. The ... constant output level at the speaker even though the signal strength at the antenna varies.

Description : Write the IF value of (i) FM ratio recevier. (ii) MW band AM.

Last Answer : (i) 10.7 Mhz (ii) 455 Khz

Description : Define fading w.r.t. wave propagation. 

Last Answer : Fading: The fluctuation in signal strength at a receiver, which is mainly due to the interference of two waves which left the same source but arrived at the destination by different paths, is known as fading. 

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.

Description : Draw the practical AM diode detector circuit. Sketch its input and output waveforms. 

Last Answer : Practical AM diode detector 1. Skip distance:-Skip distance is defined as the shortest distance from a transmitter, measured along the surface of earth at which a sky wave of fixed frequency ... had taken place from a surface located at a greater height, called Virtual height of this layer.

Description : Explain Tropospheric scatter propagation with sketch.

Last Answer : As the name implies, troposcatter uses the troposphere as the region that affects the radio signals being transmitted, returning them to Earth so that they can be received by the ... of "blurring" the overall received signal and this makes high speed data transmissions difficult.

Description : Draw and label PLL based FM detector.

Last Answer : Draw and label PLL based FM detector.

Description : Write any one application of the following range. 1. Radio frequency 2. IR frequency 3. Medium frequency 

Last Answer : Application of 1. Radio Frequency- Radar signals and communication 2. IR Frequency- LED, Laser, TV remote, Used for directed links e.g. to connect different buildings via laser links. 3. Medium Frequency- AM broadcasting.

Description : Derive a mathematical expression for AM wave.

Last Answer : Derive a mathematical expression for AM wave.

Description : Explain the working of half dipole antenna with its radiation pattern. 

Last Answer : Half wave dipole antenna diagram Explanation: 1. It is a resonant antenna 2. It is exact half wavelength (λ /2) long & open circuited at one end. 3. The dipole ... waves exist. Hence radiation pattern is bidirectional. The radiation pattern of half wave dipole antenna is -

Description : Compare sky wave and space wave propagation w.r.t. following points. (i) Frequency range (ii) Effect of fading (iii)Polarization (iv)Application

Last Answer : Sr. No  Parameters Sky Wave Propagation Space Wave Propagation 1 Frequency range 3 MHz to 30 MHz  Above 30 MHz 2 Effect of fading Problem of fading is ... horizontally Polarized 4 Application RadioBroadcasting (SW Range) Used for TV and FM broadcasting

Description : Explain Electromagnetic spectrum. 

Last Answer : The information signal should be first converted into an electromagnetic signal before transmission because the wireless transmission takes place using electromagnetic waves. The electromagnetic waves are oscillations which ... This entire range of frequency of EM waves is called EM spectrum.

Description : Explain structure of rectangular microstrip patch antenna with its radiation pattern. 

Last Answer : In telecommunication, a microstrip antenna (also known as a printed antenna) usually means an antenna fabricated using microstrip techniques on a printed circuit board (PCB).It is a kind of ... microstrip transmission line with equivalent loads on either end to represent the radiation loss.

Description : Explain why reception for high frequency band is better during night time.

Last Answer : In sky wave propagation, the transmitted signal travels into the upper atmosphere where it is bent or reflected back to earth. This bending or reflection of signal takes place due to the presence ... reflected signal and hence the reception for high frequency band is better during night time.

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 : Explain the concept of De-emphasis with neat diagram. 

Last Answer : In the De-emphasis circuit, by reducing the amplitude level of the received high frequency signal by the same amount as the increase in pre-emphasis is termed as De-emphasis. The pre- ... de-emphasis circuit is a low pass filter or integrator which allows only low frequencies to pass. 

Description : Draw the basic block diagram of Electronic communication system. State the function of transmitter.

Last Answer : Block diagram: Transmitter The function of the transmitter is to process the electrical signal from different aspects. For example in radio broadcasting the electrical signal obtained from sound ... the message signal are done just to ease the transmission of the signal through the channel.

Description : Sketch the radiation pattern of Yagi-Uda antenna.

Last Answer : Sketch the radiation pattern of Yagi-Uda antenna.

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 the signal to noise ratio in a car amplifier?

Last Answer : Signal to noise ratio is the difference between the noise floor and the reference level.

Description : Which sound cards have the lowest signal to noise ratio?

Last Answer : Soundwave sound card have an excellent sound from seven to one. This is one of the best when it comes to signal to noise ration

Description : if noise voltage =120 mv and signal voltage = 80 v , S/N ratio in dB is?

Last Answer : Answers is the place to go to get the answers you need and to ask the questions you want

Description : Stacking antenna elements A. increases sensitivity to weak signals B. will suppress odd harmonics C. decrease signal to noise ratio D. increases selectivity

Last Answer : A. increases sensitivity to weak signals

Description : Indicate the false statement. Noise figure is defined as A. the ratio of the S/N power supplied at the input terminal of a receiver or amplifier to the S/N power supplied to the output or ... under test, both working at the same temperature over the same bandwidth and fed from the same source

Last Answer : C. an unwanted form of energy tending to interfere with the proper and easy reception and reproduction of wanted signals

Description : Where is the noise generated that primarily determines the signal-to-noise ratio in a VHF (150MHz) marine-band receiver? A. Man-made noise B. In the atmosphere C. In the receiver front end D. In the ionosphere

Last Answer : C. In the receiver front end

Description : Three identical circuits having 10 dB signal noise-to-noise ratio each are connected in tandem with each other, what is the overall S/N? A. 5.23 dB B. 14.77dB C. 30 dB D. 40 dB

Last Answer : A. 5.23 dB

Description : What signal-to-noise ratio is required for satisfactory television reception? A. 10 dB B. 30 dB C. 40 dB D. 20 dB

Last Answer : C. 40 dB

Description : What causes image interference? A. Low gain B. High IF C. Poor front-end selectivity D. Low signal-to-noise ratio

Last Answer : C. Poor front-end selectivity

Description : What is the quantization signal-to-noise ratio if an 8-bit PCM code is used? A. 40 dB B. 50 dB C. 60 dB D. 65 dB

Last Answer : B. 50 dB

Description : What bandwidth is needed to support a capacity of 128 kbps when the signal power to noise power ratio in decibels is 100? A. 19224 Hz B. 3853 Hz C. 19244 Hz D. 3583 Hz

Last Answer : B. 3853 Hz

Description : Where is the noise generated that primarily determines the signal-to-noise ratio in a VHF (150 MHz) marine-band receiver? A. In the ionosphere B. In the receiver rear end C. In the receiver front end D. In the atmosphere

Last Answer : C. In the receiver front end

Description : The signal to noise ratio that is required for a satisfactory television reception. A. 30 dB B. 40 dB C. 10 dB D. 20 dB

Last Answer : B. 40 dB

Description : What signal-to-noise ratio is required for satisfactory telephone services? A. 50 dB B. 30 dB C. 40dB D. 20 dB

Last Answer : A. 50 dB

Description : The signal in a channel is measured to be 23 dB while noise in the same channel is measured to be 9 dB. The signal to noise ratio therefore is __________. A. 9/23 B. 23/9 C. 32 dB D. 14 dB

Last Answer : D. 14 dB

Description : Which of the following refers to theterms "residual error rate"? A. the number of biterrors per twenty four hours of continuous operation onanasynchronous line B. The probability that one or moreerrors ... tonoise ratio dividedby the ratio of energy perbit to noise per hertz E. None of the above

Last Answer : The probability that one or moreerrors will be undetected whenan error detection scheme is used

Description : Which performance parameter is the minimum amount of optical power required to achieve a specific bit-error rate (BER) in digital systems or a given signal-to-noise ratio (SNR) in analog systems?

Last Answer : Receiver sensitivity.

Description : Why does adding dc vice ac bias voltage to the input signal result in a poor signal-to-noise ratio (SNR)?

Last Answer : With dc bias, the SNR is poor because only a small portion of the magnetism curve is straight enough to use, thus the output signal is weak compared with the natural tape hiss.

Description : SNR is: A. Signal to Noise Ratio B. Signal to Net Ratio C. Signal to Noise Rate D. None of above

Last Answer : A. Signal to Noise Ratio

Last Answer : For a system to be designated as hi-fi, the signal to noise ratio should be at least 50 dB.

Description : Define the term electrical noise. List types of noises.

Last Answer : Electrical Noise:- It can be defined as undesirable electrical signals, which distort or interfere with an original (or desired) signal.  Types of noises:- 

Description : How do radios know the difference between noise and a signal?

Last Answer : A radio wave has a narrow band of frequency while noise has a wide band. Unless the amplitude of noise is too strong, your radio can lock on a radio station’s signal.

Description : Noise occurring in the presence of signal resulting from a mismatch between the exact value of an analog signal and the closet available quantizing step in a digital coder. A. Quantizing noise B. Thermal noise C. Impulse noise D. Crosstalk

Last Answer : A. Quantizing noise

Description : Deemphasis in the receiver in effect attenuates modulating signal components and noise in what frequency range? A. dc B. low C. intermediate D. high

Last Answer : D. high

Description : What is the reliable measurement for comparing amplifier noise characteristics? A. Thermal agitation noise B. Noise factor C. Noise margin D. Signal-to-noise

Last Answer : B. Noise factor

Description : Unwanted radio signal on assigned frequency. A. Splatter B. RFI C. Noise D. EMI

Last Answer : C. Noise

Description : Which causes a quantization noise in PCM system? A. Serial transmission errors B. The approximation of the quantized signal C. The synchronization between encoder and decoder D. Binary coding techniques

Last Answer : B. The approximation of the quantized signal

Description : Which causes a quantization noise in PCM system? A. Serial transmission errors B. The approximation of the quantized signal C. The synchronization between encoder and decoder D. Binary coding techniques

Last Answer : The approximation of the quantized signal

Description : Noise always affects the signal in a communications systems at the ________. A. transmitter B. channel C. information source D. destination

Last Answer : B. channel