If you have available number of power amplifiers with a gain of 100 each, how many such amplifiers do you need to cascade to give an overall gain of 60 dB? A. 3 B. 4 C. 5 D. 2

If you have available number of power amplifiers with a gain of 100 each, how many such
amplifiers do you need to cascade to give an overall gain of 60 dB?
A. 3
B. 4
C. 5
D. 2
by

1 Answer

Answer :

A. 3
by

Related questions

What is the effective radiated power of a repeater with 120 watts transmitter power output, 5 dB feedline loss, 4 dB duplexer and circulator loss, and 6 dB antenna gain? A. 601 W B. 240 W C. 60 W D. 379 W

Description : What is the effective radiated power of a repeater with 120 watts transmitter power output, 5 dB feedline loss, 4 dB duplexer and circulator loss, and 6 dB antenna gain? A. 601 W B. 240 W C. 60 W D. 379 W

Last Answer : C. 60 W

A dipole antenna requires to be fed with 20 kW of power to produce a given signal strength to a particular distant point. If the addition of a reflector makes the same field strength available with an input power of 11kW. What is the gain in dB, obtained by the use if the reflector. (Gain referred to this particular dipole). A. 4.75 B. 2.6 C. 1.81 D. 4.24

Description : A dipole antenna requires to be fed with 20 kW of power to produce a given signal strength to a particular distant point. If the addition of a reflector makes the same field strength available with an input power of 11kW ... Gain referred to this particular dipole). A. 4.75 B. 2.6 C. 1.81 D. 4.24

Last Answer : B. 2.6

A dipole antenna requires to be feed with 20 kW of power to produce a given signal strength to a particular distant point. If the addition of a reflector makes the same field strength available with an input power of 11 kW. What is the gain in dB obtain by the use of the reflector ? ( Gain referred to this particular dipole) A. 4.24 B. 1.81 C. 4.75 D. 2.6

Description : A dipole antenna requires to be feed with 20 kW of power to produce a given signal strength to a particular distant point. If the addition of a reflector makes the same field strength available with an input power of 11 ... ( Gain referred to this particular dipole) A. 4.24 B. 1.81 C. 4.75 D. 2.6

Last Answer : D. 2.6

What is the effective radiated power of a repeater with 100 watts transmitter power output, 5 dB feedline loss, 4 dB duplexer and circulator loss, and 10 dB antenna gain? A. 800 W B. 126 W C. 12.5 W D. 1260 W

Description : What is the effective radiated power of a repeater with 100 watts transmitter power output, 5 dB feedline loss, 4 dB duplexer and circulator loss, and 10 dB antenna gain? A. 800 W B. 126 W C. 12.5 W D. 1260 W

Last Answer : B. 126 W

The power fed to a two-bay turnstile antenna is 100 watts. If the antenna has a 2 dB power gain, what is the effective radiated power? A. 317 watts B. 158 watts C. 200 watts D. 400 watts

Description : The power fed to a two-bay turnstile antenna is 100 watts. If the antenna has a 2 dB power gain, what is the effective radiated power? A. 317 watts B. 158 watts C. 200 watts D. 400 watts

Last Answer : B. 158 watts

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

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

If three stage amplifiers has individual stage gain of 10 db, 5 db & 12 db then the total gain

Last Answer : If three stage amplifiers has individual stage gain of 10 db, 5 db & 12 db then the total gain 27 db

Three telephone circuits, each having an S/N ratio of 44 dB, are connected in tandem. What is the overall S/N ratio? A. 44 dB B. 39.2 dB C. 41 dB D. 43.52 dB

Description : Three telephone circuits, each having an S/N ratio of 44 dB, are connected in tandem. What is the overall S/N ratio? A. 44 dB B. 39.2 dB C. 41 dB D. 43.52 dB

Last Answer : B. 39.2 dB

Part of a microwave link can be approximated by free space conditions. The antenna gain are each 40 dB, the frequency is 10 GHz, and the path length is 80 km. Calculate the receive power for a transmitted power of 10 W? A. 0.871 μW B. 871 μW C. 0.871 mW D. 871 nW

Description : Part of a microwave link can be approximated by free space conditions. The antenna gain are each 40 dB, the frequency is 10 GHz, and the path length is 80 km. Calculate the receive power for a transmitted power of 10 W? A. 0.871 μW B. 871 μW C. 0.871 mW D. 871 nW

Last Answer : A. 0.871 μW

What is the gain, in dB of a helical antenna with diameter of λ/3, 10 turns at pitch of λ/4, used at 100 MHz? A. 16 B. 41.1 C. 31.4 D. 1.25

Description : What is the gain, in dB of a helical antenna with diameter of λ/3, 10 turns at pitch of λ/4, used at 100 MHz? A. 16 B. 41.1 C. 31.4 D. 1.25

Last Answer : A. 16

If an antenna has a gain of 3 dB, it increases the output of the transmitter by A. 10,000 times B. 1000 times C. 100 times D. 1 million times

Description : If an antenna has a gain of 3 dB, it increases the output of the transmitter by A. 10,000 times B. 1000 times C. 100 times D. 1 million times

Last Answer : B. 1000 times

The noise figure of the first circuit in tandem connection is 10.5 dB while its power gain is 15, what is the over all noise figure if the second circuit has a noise figure of 11 dB? A. 11.59 dB B. 11.23 dB C. 10.79 dB D. 10.5 dB

Description : The noise figure of the first circuit in tandem connection is 10.5 dB while its power gain is 15, what is the over all noise figure if the second circuit has a noise figure of 11 dB? A. 11.59 dB B. 11.23 dB C. 10.79 dB D. 10.5 dB

Last Answer : C. 10.79 dB

What is the effective radiated power of a repeater with 75 watts transmitter power output, 5 dB feedline loss, 4 dB duplexer and circulator loss, and 6 dB antenna gain? A. 37.6 W B. 237 W C. 150 W D. 23.7 W

Description : What is the effective radiated power of a repeater with 75 watts transmitter power output, 5 dB feedline loss, 4 dB duplexer and circulator loss, and 6 dB antenna gain? A. 37.6 W B. 237 W C. 150 W D. 23.7 W

Last Answer : A. 37.6 W

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

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

What is the effective radiated power of a repeater with 200 watts transmitter power output, 4 dB feline loss, 4 dB duplexer and circulator loss, and 10 dB antenna gain? A. 317 W B. 2000 W C. 126 W D. 260 W

Description : What is the effective radiated power of a repeater with 200 watts transmitter power output, 4 dB feline loss, 4 dB duplexer and circulator loss, and 10 dB antenna gain? A. 317 W B. 2000 W C. 126 W D. 260 W

Last Answer : A. 317 W

What is the effective radiated power of a repeater with 75 watts transmitter power output, 4 dB feedline loss, 3 dB duplexer and circulator loss, and 10 dB antenna gain? A. 600 W B. 75 W C. 18.75 W D. 150 W

Description : What is the effective radiated power of a repeater with 75 watts transmitter power output, 4 dB feedline loss, 3 dB duplexer and circulator loss, and 10 dB antenna gain? A. 600 W B. 75 W C. 18.75 W D. 150 W

Last Answer : D. 150 W

What is the effective radiated power of a repeater with 50 watts transmitter power output \, 4 dB feedline loss, 3 dB duplexer and circulator loss, and 6 dB antenna gain? A. 158 W B. 39.7 W C. 251 W D. 69.9 W

Description : What is the effective radiated power of a repeater with 50 watts transmitter power output \, 4 dB feedline loss, 3 dB duplexer and circulator loss, and 6 dB antenna gain? A. 158 W B. 39.7 W C. 251 W D. 69.9 W

Last Answer : B. 39.7 W

Determine the gain of a 6 ft. parabolic dish operating at 1800 MHz. A. 30 dB B. 11.2 dB C. 15.5 dB D. 28.17 dB

Description : Determine the gain of a 6 ft. parabolic dish operating at 1800 MHz. A. 30 dB B. 11.2 dB C. 15.5 dB D. 28.17 dB

Last Answer : D. 28.17 dB

What is the gain of an antenna over a half-wavelength dipole when it has 6 dB gain over an isotropic radiator? A. 6.0 dB B. 8.1 dB C. 3.9 dB D. 10.0 dB

Description : What is the gain of an antenna over a half-wavelength dipole when it has 6 dB gain over an isotropic radiator? A. 6.0 dB B. 8.1 dB C. 3.9 dB D. 10.0 dB

Last Answer : C. 3.9 dB

What is the theoretical gain of a Hertzian dipole? A. 1.76 dB B. 2.15 dB C. 3 dB D. 0 dB

Description : What is the theoretical gain of a Hertzian dipole? A. 1.76 dB B. 2.15 dB C. 3 dB D. 0 dB

Last Answer : A. 1.76 dB

What is the gain of the Hertzian dipole over isotropic antenna? A. 1.64 dB B. 2.15 dB C. 1.76 dB D. 1.55 dB

Description : What is the gain of the Hertzian dipole over isotropic antenna? A. 1.64 dB B. 2.15 dB C. 1.76 dB D. 1.55 dB

Last Answer : C. 1.76 dB

How does the gain of a parabolic dish type antenna change when the operating frequency is doubled? A. Gain does not change B. Gain is multiplied by 0.707 C. Gain increases 6 dB D. Gain increases 3 dB

Description : How does the gain of a parabolic dish type antenna change when the operating frequency is doubled? A. Gain does not change B. Gain is multiplied by 0.707 C. Gain increases 6 dB D. Gain increases 3 dB

Last Answer : C. Gain increases 6 dB

Determine the dB gain of a receiving antenna which delivers a microvolt signal to a transmission line over that of an antenna that delivers a 20 microvolt signal under identical circumstances. A. 10 dB B. 6 dB C. 3 dB D. 8 dB

Description : Determine the dB gain of a receiving antenna which delivers a microvolt signal to a transmission line over that of an antenna that delivers a 20 microvolt signal under identical circumstances. A. 10 dB B. 6 dB C. 3 dB D. 8 dB

Last Answer : B. 6 dB

Theoretical gain of a hertzian dipole A. 0 dB B. 1.76 dB C. 3 dB D. 2.15 dB

Description : Theoretical gain of a hertzian dipole A. 0 dB B. 1.76 dB C. 3 dB D. 2.15 dB

Last Answer : B. 1.76 dB

Gain of an isotropic antenna A. -1 dB B. 1 dB C. 0 dB D. 2 dB

Description : Gain of an isotropic antenna A. -1 dB B. 1 dB C. 0 dB D. 2 dB

Last Answer : C. 0 dB

What is the gain of four identically polarized antennas stacked one above the other and fed in phase? A. 3 dB over the gain of one antenna B. 10 dB over the gain of one antenna C. 4 dB over the gain of one antenna D. 6 dB over the gain of one antenna

Description : What is the gain of four identically polarized antennas stacked one above the other and fed in phase? A. 3 dB over the gain of one antenna B. 10 dB over the gain of one antenna C. 4 dB over the gain of one antenna D. 6 dB over the gain of one antenna

Last Answer : D. 6 dB over the gain of one antenna

If a transmission line has a power loss of 6 dB per 100 feet, what is the power at the feed point to the antenna at the end of a 200 foot transmission line fed by a 100 watt transmitter? A. 70 watts B. 50 watts C. 25 watts D. 6 watts

Description : If a transmission line has a power loss of 6 dB per 100 feet, what is the power at the feed point to the antenna at the end of a 200 foot transmission line fed by a 100 watt transmitter? A. 70 watts B. 50 watts C. 25 watts D. 6 watts

Last Answer : D. 6 watts

A reading of -50 dBm on the disturbing pair, and -80 on the disturbed pair equals _____ dB of crosstalk coupling. A. 20 B. 30 C. 60 D. 25

Description : A reading of -50 dBm on the disturbing pair, and -80 on the disturbed pair equals _____ dB of crosstalk coupling. A. 20 B. 30 C. 60 D. 25

Last Answer : B. 30

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

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

For a loudness level between 110 and 120 dB, the maximum daily exposure limit is ____ minute (s). A. 1 B. 60 C. 20 D. 45

Description : For a loudness level between 110 and 120 dB, the maximum daily exposure limit is ____ minute (s). A. 1 B. 60 C. 20 D. 45

Last Answer : A. 1

At what loudness level do pitch (in mels) and frequency (in Hz) are numerically equal? A. 0 dB B. 20 dB C. 60 dB D. 40 dB

Description : At what loudness level do pitch (in mels) and frequency (in Hz) are numerically equal? A. 0 dB B. 20 dB C. 60 dB D. 40 dB

Last Answer : D. 40 dB

Why are frequency modulation transmitters more efficient? A. Because their power is increased by class C amplifiers B. Because their power is increased by class A amplifiers C. Because their power is increased by class B amplifiers D. Because their power is increased by class AB amplifiers

Description : Why are frequency modulation transmitters more efficient? A. Because their power is increased by class C amplifiers B. Because their power is increased by class A amplifiers C. Because their power is increased by class B amplifiers D. Because their power is increased by class AB amplifiers

Last Answer : A. Because their power is increased by class C amplifiers

Paresh purchased an I-pod for Rs. 7500 and sold it at the gain of 24%. From that amount he purchased another I-pod and sold it at the loss of 20%. What is his overall gain/loss? (a) Loss of Rs. 100 (b) Gain of Rs. 60 (c) Loss of Rs. 60 (d) Neither gain nor loss (e) Gain of Rs. 100

Description : Paresh purchased an I-pod for Rs. 7500 and sold it at the gain of 24%. From that amount he purchased another I-pod and sold it at the loss of 20%. What is his overall gain/loss? (a) Loss of Rs. 100 (b) Gain of Rs. 60 (c) Loss of Rs. 60 (d) Neither gain nor loss (e) Gain of Rs. 100

Last Answer : (c) Loss of Rs. 60

An amplifier has input power of 2 microwatts. The power gain of the amplifier is 60 dB. The output power will be

Description : An amplifier has input power of 2 microwatts. The power gain of the amplifier is 60 dB. The output power will be

Last Answer : An amplifier has input power of 2 microwatts. The power gain of the amplifier is 60 dB. The output power will be 2 watts

The noise from an airplane engine 100 ft from an observer is found to have an intensity of 45dB. What will be the intensity when the plane flies overhead at an altitude of 1 mi? A. 10.5 dB B. 34.5 dB C. 35 dB D. 20.5 dB

Description : The noise from an airplane engine 100 ft from an observer is found to have an intensity of 45dB. What will be the intensity when the plane flies overhead at an altitude of 1 mi? A. 10.5 dB B. 34.5 dB C. 35 dB D. 20.5 dB

Last Answer : A. 10.5 dB

What is the front-to-back ratio of an antenna which radiates 500 watts in a northernly direction and 50 watts in a southernly direction? A. 25000 dB B. 10 dB C. 100 dB D. 20 dB

Description : What is the front-to-back ratio of an antenna which radiates 500 watts in a northernly direction and 50 watts in a southernly direction? A. 25000 dB B. 10 dB C. 100 dB D. 20 dB

Last Answer : B. 10 dB

When the elevation angle of a geostationary satellite is 23˚ and the transmitting frequency is 3840 MHz, what is the free space loss in dB? A. 196 dB B. 200 dB C. 150 dB D. 100 dB

Description : When the elevation angle of a geostationary satellite is 23˚ and the transmitting frequency is 3840 MHz, what is the free space loss in dB? A. 196 dB B. 200 dB C. 150 dB D. 100 dB

Last Answer : A. 196 dB

The total space loss of transmission and reception for two ground stations with uplink frequency 8GHz and a downlink of 6 GHz with angle of elevations of 3˚ and 7˚ A respectively is A. 403 dB B. 100 dB C. 20 dB D. 215 dB

Description : The total space loss of transmission and reception for two ground stations with uplink frequency 8GHz and a downlink of 6 GHz with angle of elevations of 3˚ and 7˚ A respectively is A. 403 dB B. 100 dB C. 20 dB D. 215 dB

Last Answer : A. 403 dB

What is the approximate path loss from satellite-to-earth station? A. 100 dB B. 150 dB C. 175 dB D. 200 dB

Description : What is the approximate path loss from satellite-to-earth station? A. 100 dB B. 150 dB C. 175 dB D. 200 dB

Last Answer : D. 200 dB

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.

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

In a triple conversion superheterodyne receiver, diode mixer stages are operated A. In the linear region B. In the nonlinear region C. As class A amplifiers D. As class B amplifiers

Description : In a triple conversion superheterodyne receiver, diode mixer stages are operated A. In the linear region B. In the nonlinear region C. As class A amplifiers D. As class B amplifiers

Last Answer : B. In the nonlinear region

What are feed back amplifiers?

Description : What are feed back amplifiers?

Last Answer : Amplifiers which uses feed back principle is called as feed back amplifiers.

How are amplifiers classified according to the transistor configuration?

Description : How are amplifiers classified according to the transistor configuration?

Last Answer : 1. Common emitter amplifier 2. Common base amplifier 3. Common collector amplifier

How are amplifiers classified according to the input?

Description : How are amplifiers classified according to the input?

Last Answer : 1. Small – signal amplifier 2. Large – signal amplifier

List the applications of Log amplifiers:

Description : List the applications of Log amplifiers:

Last Answer : 1.Analog computation may require functions such as lnx, log x, sin hx etc. These functions can be performed by log amplifiers 2.Log amplifier can perform direct dB display on digital voltmeter and spectrum analyzer 3.Log amplifier can be used to compress the dynamic range of a signal

Define each of following terms of operational amplifiers i) Slew rate ii) Input offset voltage iii) Voltage gain iv) Input capacitance

Description : Define each of following terms of operational amplifiers i) Slew rate ii) Input offset voltage iii) Voltage gain iv) Input capacitance

Last Answer : i) Slew rate:- Maximum rate of change of o/p voltage per unit of time. It is express in volt/µsec.  ii) Input offset voltage:- The voltage that must be applied between two ... capacitance that can be measured at either be inverting or non-inverting terminal with other terminal connected to ground.

What is the difference between available power and power budget? A. Power margin B. Extra power C. Fade margin D. System gain

Description : What is the difference between available power and power budget? A. Power margin B. Extra power C. Fade margin D. System gain

Last Answer : A. Power margin

_______ is referred as the difference between available power and power budget? A. Fade margin B. Power margin C. Nominal gain D. Power dissipation

Description : _______ is referred as the difference between available power and power budget? A. Fade margin B. Power margin C. Nominal gain D. Power dissipation

Last Answer : B. Power margin

A differential amplifier has a differential gain of 28000 and CMRR is 60 dB. What will be the value of common

Description : A differential amplifier has a differential gain of 28000 and CMRR is 60 dB. What will be the value of common mode gain? A) Ac = 0.125 B) Ac = 0.33 C) Ac = 3 D) Ac = 28 

Last Answer : A differential amplifier has a differential gain of 28000 and CMRR is 60 dB. What will be the value of common mode gain? A) Ac = 0.125 B) Ac = 0.33 C) Ac = 3 D) Ac = 28