Two resistors, 20kΩ, and 50kΩ are at ambient temperature. Calculate for a bandwidth equal
to 100kHz, the thermal noise voltage for the two resistors connected in parallel.
A. 0.4782µV
B. 4278 µV
C. 4.78 µV
D. 47.8 µV

1 Answer

Answer :

C. 4.78 µV

Related questions

Description : An amplifier operating over the frequency range of 455 to 460 kHz has a 200 kΩ input resistor. What is the RMS noise voltage at the input to this amplifier if the ambient temperature is 17˚C ? A. 40 µV B. 4.0 µV C. 400 µV

Last Answer : B. 4.0 µV

Description : The noise output of a resistor is amplified by a noiseless amplifier having a gain of 60 and a bandwidth of 20 kHz. A meter connected at the output of the amplifier reads 1mV RMS. If the bandwidth of the amplifier is reduced to ... does the meter read now? A. 0.5 mV B. 0.5 µV C. 5.0 mV D. 5.0 µV

Last Answer : A. 0.5 mV

Description : What is the noise voltage across a 300Ω input resistance to a TV set with a 6MHz bandwidth and temperature of 30˚C? A. 2.3 µV B. 3.8µV C. 5.5µV D. 5.4µV

Last Answer : C. 5.5µV

Description : At 17˚ C, the noise voltage generated by 5kΩ resistor, operating over a bandwidth of 20KHz is A. 1.3 nV B. 1.3 µV C. 1.3 pV D. 1.3 mV

Last Answer : B. 1.3 µV

Description : Three resistors connected in parallel have values of 12 kΩ, 20kΩ, and 30kΩ. What is the equivalent resistance? A37. 6kΩ Q38. Two resistors connected in parallel have values of 10 kΩ and 30kΩ. What is eht equivalent resistance?

Last Answer : 7.5kΩ

Description : Calculate the noise figure of the receiver whose RF amplifier has an input resistance of 1000Ω and an equivalent shot-noise resistance of 2000Ω, a gain of 25 and load resistance of 125 kΩ. Given that the bandwidth is 1. ... to an antenna with an impedance of 75Ω. A. 30.3 B. 3.03 C. 303 D. .303

Last Answer : A. 30.3

Description : The square of the thermal noise voltage generated by a resistor is proportional to A. its resistance B. its temperature C. the bandwidth over which it is measured D. All of the above

Last Answer : D. All of the above

Description : Indicate the false statement. A. HF mixer are generally noisier than HF amplifiers. B. Impulse noise voltage is dependent on bandwidth C. Thermal noise is independent of the frequency at which is measured. D. Industrial noise is usually of the impulse type.

Last Answer : B. Impulse noise voltage is dependent on bandwidth

Description : A receiver connected to an antenna whose resistance is 50 Ω has an equivalent noise resistance of 30Ω. Calculate its equivalent noise temperature if the noise figure is equal to 1.6. A. 17.4 K B. 174K C. 1.74K D. 17K

Last Answer : B. 174K

Description : Indicate the false statement A. The noise generated in a resistance or the resistive component of any impedance is random. B. Random noise power is proportional to the bandwidth over which is measured ... exist D. All formula referring to random noise are applicable only to the value of such noise.

Last Answer : C. A random voltage across the resistor does not exist

Description : The first stage of a two-stage amplifier has a voltage gain of 10, a 600 Ω input resistor, a 1600Ω equivalent noise resistance and 27kΩ output resistor. For the second stage, these values are 25, 81kΩ, 19kΩ, and 1MΩ, ... this two stage amplifier. A. 2,518 kΩ B. 2,518 Ω C. 251.8 Ω D. 12,518 Ω

Last Answer : B. 2,518 Ω

Last Answer : Req= (1/1200 +1/560 + 1/2.1)^-1        = 2.1 ohms RT= 2.1 + 7.8      = 9.9 ohms IT = V/R = 24/9.9                = 2.4 A Veq= R I =  2.1 2 ... 7.8         = 12.096 w                 = 44.928 w _________________________________________ By: Ellis-Junior Kamatjipose [email protected]

Description : Noise can be reduced by A. widening the bandwidth B. narrowing the bandwidth C. increasing temperature D. increasing transistor current levels

Last Answer : B. narrowing the bandwidth

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 : Which does not effect noise in a channel? A. None of these B. Bandwidth C. Temperature D. Quantizing level

Last Answer : D. Quantizing level

Description : A battery is connected to a circuit containing three resistors in parallel. The values of the three resistors are 2 ohms, 3 ohms, and 6 ohms. What is the voltage of the battery if the total circuit current is 12 amps? A. 2 volts B. 6 volts C. 12 volts D. 24 volt

Last Answer : Answer: C

Description : Noise from random acoustic or electric noise that has equal energy per cycle over a specified total frequency band. A. Gaussian noise B. Whiter noise C. Thermal noise D. All of the above

Last Answer : D. All of the above

Description : Noise from random acoustic or electric noise that has equal per cycle over a specified total frequency band. A. Thermal noise B. White noise C. Gaussian noise D. All of these

Last Answer : D. All of these

Description : Which of the following is not a way of minimizing if not eliminating noise? A. Use redundancy B. Increase transmitted power C. Reduce signaling rate D. Increase channel bandwidth

Last Answer : D. Increase channel bandwidth

Description : The total noise power present in a 1-Hz bandwidth . A. Noise density B. Noise figure C. Noise limit D. Noise intensity

Last Answer : A. Noise density

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 : Emission on a frequency or frequencies immediately outside the necessary bandwidth which result from the modulation process except spurious emission. A. Radiation B. Noise C. Out of the band D. Interference

Last Answer : C. Out of the band

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 : Four equal resistors are connected in parallel, each resistor has an ohmic value of 100 ohms, what is the equivalent resistance?

Last Answer : 25 ohms

Description : Three equal resistors connected in series with a source of e m f together dissipate 10 W of power each. What will be the power dissipated if the same resistors are connected in parallel across the same source of e m f? a. 40 W b. 90W c. 100W d. 120W

Last Answer : b. 90W

Description : Considered as the main source of an internal noise. A. Device imperfection B. Thermal agitation C. Temperature change D. Flicker

Last Answer : B. Thermal agitation

Description : Which of the following is one of the possible causes for a slow drift of frequency in a self exited transmitter oscillator circuits resulting to a poor frequency stability? A. Poor soldered connections ... , or antenna circuits D. DC and RF heating of resistors, causing then to change values.

Last Answer : D. DC and RF heating of resistors, causing then to change values.

Description : Two unpedauces given by Z1 = 10 + j5 and Z2 = 8 + j9 are joined in parallel and connected across a voltage of V = 200 + j0. Calculate the circuit current and branch currents. Draw the vector diagram.

Last Answer : Solution: Given, Z1=10+j5, Z2=8+j9, V=200+j0

Description : ECE Board Exam March 1996 A receiver connected to an antenna whose resistance is 50 ohms has an equivalent noise resistance of 30 ohms. What is the receiver’s noise temperature? A. 754 K B. 464 K C. 174 K D. 293 K

Last Answer : C. 174 K

Description : Two 10 Ω resistors are connected in parallel, their equivalent resistance isA. 5 Ω B. 0.2 Ω C. 15 Ω D. 20 Ω

Last Answer :  5 Ω

Description : One of the following is not a useful quantity for comparing the noise performance receivers. A. Input noise voltage B. Equivalent noise resistance C. Noise temperature D. Noise figure.

Last Answer : A. Input noise voltage

Description : It is the thermal noise power normalized to 1- Hz bandwidth:

Last Answer : noise power density

Description : . The inner wall of a furnace is at a temperature of 700°C. The composite wall is made of two substances, 10 and 20 cm thick with thermal conductivities of 0.05 and 0.1 W.m-1.°C-1 respectively. The ambient air is at 30°C ... from the outer surface in W.m-2 is (A) 165.4 (B) 167.5 (C) 172.5 (D) 175

Last Answer : (A) 165.4

Description : Crosstalk due to incomplete suppression of sidebands or to intermodulation of two or more frequency-multiplexed channels which is unintelligible is classified as A. Impulse noise B. Thermal noise C. Quantizing noise D. Miscellaneous noise

Last Answer : D. Miscellaneous noise

Description : A noise whose source is within the solar system. A. Solar noise B. Thermal noise C. Cosmic noise D. Johnson Noise

Last Answer : A. Solar noise

Description : External noise originating outside the solar system A. Cosmic noise B. Solar noise C. Thermal noise D. Lunar noise

Last Answer : A. Cosmic noise

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 : Most internal noise comes from A. Shot noise B. Transit-time noise C. Thermal agitation D. Skin effect

Last Answer : C. Thermal agitation

Description : The value of the resistor creating thermal noise is doubled. The noise power generated is therefore. A. halved B. quadrupled C. doubled D. unchanged

Last Answer : D. unchanged

Description : ________ is an electric noise produced by thermal agitation of electrons in conductor and semiconductor. A. External noise B. Internal noise C. Thermal noise D. Flicker

Last Answer : C. Thermal noise

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 : Background noise is the same as the C. Thermal noise D. Gaussian noise 24. ECE Board Ex

Last Answer : A. Impulse noise

Description : Noise caused by the thermal agitation of electrons in resistance. A. All of these B. Thermal noise C. Johnson’s noise D. White noise

Last Answer : A. All of these

Description : Two resistors of resistances `2Omega` and `6Omega` are connected in parallel. This combination is then connected to a battery of emf 2 V and internal

Last Answer : Two resistors of resistances `2Omega` and `6Omega` are connected in parallel. This combination is then connected to a ... . `(4)/(17)A` D. `1 A`

Description : What must be the same for two resistors that are connected in a parallel?

Last Answer : It is not necessary for anything about them to be the same.All that is necessary is that they create the desired equivalent resistor, having the correct resistance and power dissipation rating without overstressing either resistor.

Description : Two identical resistors are connected in parallel and consume 200 watts together. A third identical resistor is added in parallel. The total power consumed is: w) 100 watts x) 200 watts y) 300 watts z) 400 watts

Last Answer : ANSWER: Y -- 300 WATTS

Description : When two 100 kΩ resistors are connected in parallel, net resistance is

Last Answer : When two 100 kΩ resistors are connected in parallel, net resistance is 50 kΩ

Last Answer : If two parallel-connected resistors dissipate 6 watts and 10 watts of power, then 16 watts is the total power loss.

Description : A `5 Omega` resistor is connected in series with a parallel combination of n resistors of `6 Omega` each. The equivalent resistance is `7 Omega`. Find

Last Answer : A `5 Omega` resistor is connected in series with a parallel combination of n resistors of `6 Omega ... The equivalent resistance is `7 Omega`. Find n.