In Radio Communication, the signals emitted by transmitting antenna are reflected on

In Radio Communication, the signals emitted by transmitting antenna are
reflected on
by

1 Answer

Answer :

Ionosphere
by

Related questions

In radio-communication, the signals emitted by transmitting antenna are reflected on – (1) stratosphere (2) ozonosphere (3) ionosphere (4) troposphere

Description : In radio-communication, the signals emitted by transmitting antenna are reflected on – (1) stratosphere (2) ozonosphere (3) ionosphere (4) troposphere

Last Answer : (3) ionosphere Explanation: The lower atmosphere is more or less transparent to radio waves. However, the ionosphere reflects back the radio waves. Thus, a signal emitted by an antenna from a ... on the surface of Earth in the following two ways: ground wave propagation and sky wave propagation.

In radio-communication, the signals emitted by transmitting antenna are reflected on (1) stratosphere(2) ozonosphere (3) ionosphere (4) troposphere

Description : In radio-communication, the signals emitted by transmitting antenna are reflected on (1) stratosphere(2) ozonosphere (3) ionosphere (4) troposphere

Last Answer : ionosphere

For a space wave transmission, the radio horizon distance of a transmitting antenna with a height of 100 meters is approximately:A. 10 km B. 40 km C. 100 km D. 400 km

Description : For a space wave transmission, the radio horizon distance of a transmitting antenna with a height of 100 meters is approximately: A. 10 km B. 40 km C. 100 km D. 400 km

Last Answer : B. 40 km

What is a dummy antenna? A. One which is used as a reference for gain measurements B. And antenna used for hand-held radio C. An non-directional transmitting antenna D. A non-radiating load for a transmitter used for testing

Description : What is a dummy antenna? A. One which is used as a reference for gain measurements B. And antenna used for hand-held radio C. An non-directional transmitting antenna D. A non-radiating load for a transmitter used for testing

Last Answer : D. A non-radiating load for a transmitter used for testing

If a transmitting antenna is 100 meters high and a separate receiving antenna is 64 meters high, what is the maximum space wave communication distance possible between them? A. 18 km B. 72 km C. 164 km D. 656 km

Description : If a transmitting antenna is 100 meters high and a separate receiving antenna is 64 meters high, what is the maximum space wave communication distance possible between them? A. 18 km B. 72 km C. 164 km D. 656 km

Last Answer : B. 72 km

Radio wave concentration in the direction of the signal emitted by a directional antenna. A. Back lobe radiation B. Side lobe radiation C. Major lobe radiation D. Transmitted signal

Description : Radio wave concentration in the direction of the signal emitted by a directional antenna. A. Back lobe radiation B. Side lobe radiation C. Major lobe radiation D. Transmitted signal

Last Answer : C. Major lobe radiation

Pick out the wrong statement (A) The concentric atmosphere layer just above troposphere is called stratosphere, which is rich in ozone (B) Mesosphere is characterised by very low atmospheric pressure and low temperature (C) Troposphere is a dusty zone containing water vapor and clouds (D) The radio waves used in the long distance radio communication are reflected back to earth by stratosphere

Description : Pick out the wrong statement (A) The concentric atmosphere layer just above troposphere is called stratosphere, which is rich in ozone (B) Mesosphere is characterised by very low atmospheric ... radio waves used in the long distance radio communication are reflected back to earth by stratosphere

Last Answer : (D) The radio waves used in the long distance radio communication are reflected back to earth by stratosphere

Remote sensing techniques make use of the properties of ___________ emitted, reflected or diffracted by the sensed objects: (A) Electric waves (B) Sound waves (C) Electromagnetic waves (D) Wind waves

Description : Remote sensing techniques make use of the properties of ___________ emitted, reflected or diffracted by the sensed objects: (A) Electric waves (B) Sound waves (C) Electromagnetic waves (D) Wind waves

Last Answer : Answer: Option C

Pick up the correct statement from the following: (A) The minimum frequency of light for which no electrons are emitted, is called threshold frequency (B) Polarising angle of glass is 57.5° (C) At the polarising angle, the reflected and refracted rays are orthogonal (D) All the above

Description : Pick up the correct statement from the following: (A) The minimum frequency of light for which no electrons are emitted, is called threshold frequency (B) Polarising angle of glass is 57.5° (C) At the polarising angle, the reflected and refracted rays are orthogonal (D) All the above

Last Answer : Answer: Option D

Pick up the correct statement from the following: (A) A graphical representation of spectral reflectance verses the various growth stages of a crop, depicts a phonologic patternB) The changes in the polarisation of the radiation reflected or emitted by an object, is known as polarisation variation (C) The degree of polarisation is a characteristic of the object which helps in the identification of the object (D) All of these

Description : Pick up the correct statement from the following: (A) A graphical representation of spectral reflectance verses the various growth stages of a crop, depicts a phonologic pattern B) The changes in ... characteristic of the object which helps in the identification of the object (D) All of these

Last Answer : Answer: Option D

We can see non luminous object ,when the light a) emitted by the object falls on the eye . b) is reflected from the object towards eye . c) completely passes through the object . d) gets completely absorbed by object .

Description : We can see non luminous object ,when the light a) emitted by the object falls on the eye . b) is reflected from the object towards eye . c) completely passes through the object . d) gets completely absorbed by object .

Last Answer : b) is reflected from the object towards eye .

If a carrier wave of 1000 kHz is used to carry the signal, the length of transmitting antenna will be equal to _______. (1) 300 m (2) 30 m (3) 3 m (4) 0.3 m

Description : If a carrier wave of 1000 kHz is used to carry the signal, the length of transmitting antenna will be equal to _______. (1) 300 m (2) 30 m (3) 3 m (4) 0.3 m

Last Answer : (1) 300 m Explanation: h = 3 × 108/106 = 300 m

Stacking elements in a transmitting antenna system A. increases the field strength at the receiving antenna B. increases the directivity of the transmitter antenna C. decrease the size of the lobe in the radiation pattern D. both A and B

Description : Stacking elements in a transmitting antenna system A. increases the field strength at the receiving antenna B. increases the directivity of the transmitter antenna C. decrease the size of the lobe in the radiation pattern D. both A and B

Last Answer : D. both A and B

A receiver is located 64 km from a space wave transmitting antenna that is 100 meters high. Find the required height of the receiving antenna. A. 36 meters high B. 64 meters high C. 100 meters high D. 182.25 meters high

Description : A receiver is located 64 km from a space wave transmitting antenna that is 100 meters high. Find the required height of the receiving antenna. A. 36 meters high B. 64 meters high C. 100 meters high D. 182.25 meters high

Last Answer : A. 36 meters high

If a transmitting antenna is placed close to the ground, how should the antenna be polarized to give the greatest signal strength?

Description : If a transmitting antenna is placed close to the ground, how should the antenna be polarized to give the greatest signal strength?

Last Answer : Vertically polarized.

What radar component permits the use of a single antenna for both transmitting and receiving?

Description : What radar component permits the use of a single antenna for both transmitting and receiving?

Last Answer : Duplexer.

What precautions must be taken when sweeping a transmitting antenna?

Description : What precautions must be taken when sweeping a transmitting antenna?

Last Answer : You must ensure that power induced from any adjacent transmitting antennas does not damage your test equipment.

The various properties of a transmitting antenna can apply equally to the same antenna when it is used as a receiving antenna. What term is used for this property?

Description : The various properties of a transmitting antenna can apply equally to the same antenna when it is used as a receiving antenna. What term is used for this property?

Last Answer : Reciprocity of antennas.

In any transmitting antenna system, efficiency primarily depends upon

Last Answer : In any transmitting antenna system, efficiency primarily depends upon radiation resistance.

A form of regenerative repeater for transmitting signals over a long cable received through a relay in a clearer form. A. Active generator B. Active repeater C. Interpolator D. Audio generator

Description : A form of regenerative repeater for transmitting signals over a long cable received through a relay in a clearer form. A. Active generator B. Active repeater C. Interpolator D. Audio generator

Last Answer : C. Interpolator

The sensor that receive sound echoes without transmitting their own sound signals is called A : Active Sonar B : Passive Sonar C : Radar D : Laser Rangefinder

Description : The sensor that receive sound echoes without transmitting their own sound signals is called A : Active Sonar B : Passive Sonar C : Radar D : Laser Rangefinder

Last Answer : B : Passive Sonar

What would happen if you plugged an FM transmitter into a radio's headphone jack and set the radio to the transmitter's transmitting frequency?

Description : What would happen if you plugged an FM transmitter into a radio's headphone jack and set the radio to the transmitter's transmitting frequency?

Last Answer : You would get a positive feedback loop, probably resulting in an audible tone. The amplitude would be limited by the transmitter’s modulation limiter, so all you’d have is a very ordinary oscillator.

What is a selective fading effect? A. A fading effect caused by small changes in beam heading at the receiving station. B. A fading effect caused by phase differences between radio wave components of the same transmission, as experienced at the receiving station. C. A fading effect caused by large changes in the height of the ionosphere, as experienced at the receiving station D. A fading effect caused by time differences between the receiving and transmitting stations.

Description : What is a selective fading effect? A. A fading effect caused by small changes in beam heading at the receiving station. B. A fading effect caused by phase differences between radio wave ... station D. A fading effect caused by time differences between the receiving and transmitting stations.

Last Answer : B. A fading effect caused by phase differences between radio wave components of the same transmission, as experienced at the receiving station.

What is the major cause of selective fading? A. Small changes in the beam heading at the receiving station. B. Large changes in the height of the ionosphere, as experience at the receiving station. C. Time differences between the receiving and transmitting stations. D. Phase differences between radio wave components of the same transmission, as experienced at the receiving station.

Description : What is the major cause of selective fading? A. Small changes in the beam heading at the receiving station. B. Large changes in the height of the ionosphere, as experience at the ... Phase differences between radio wave components of the same transmission, as experienced at the receiving station.

Last Answer : D. Phase differences between radio wave components of the same transmission, as experienced at the receiving station.

The conversion of digital signal into analog for purposes of transmitting into the telephone line is done through ______. A. ISDN B. Radio C. RS232C D. Modem

Description : The conversion of digital signal into analog for purposes of transmitting into the telephone line is done through ______. A. ISDN B. Radio C. RS232C D. Modem

Last Answer : D. Modem

Refers to an effect of selective fading. A. A fading effect caused by phase differences between radio wave components of the same transmission, as experienced at the receiving station. B. A fading effect caused by small changes in beam heading at the receiving station. C. A fading effect caused by the time differences between the receiving and transmitting stations. D. A fading effect caused by large changes in the height of the ionosphere, as experienced at the receiving station.

Description : Refers to an effect of selective fading. A. A fading effect caused by phase differences between radio wave components of the same transmission, as experienced at the receiving station. B. A fading ... caused by large changes in the height of the ionosphere, as experienced at the receiving station.

Last Answer : A. A fading effect caused by phase differences between radio wave components of the same transmission, as experienced at the receiving station.

Production of radiation by a radio transmitting station A. Monitoring B. Emission C. Radiation D. Transmission

Description : Production of radiation by a radio transmitting station A. Monitoring B. Emission C. Radiation D. Transmission

Last Answer : B. Emission

ECE Board Exam March 1996 It is a spacecraft placed in orbit around the earth carrying onboard microwave receiver and transmitting equipments. A. Fiber optic equipment B. Communications satellite C. Wireless radio system D. Coaxial cable syste

Description : ECE Board Exam March 1996 It is a spacecraft placed in orbit around the earth carrying onboard microwave receiver and transmitting equipments. A. Fiber optic equipment B. Communications satellite C. Wireless radio system D. Coaxial cable syste

Last Answer : B. Communications satellite

Designed to receive a signal from a transmitting station on the ground and retransmit it to a receiving station located elsewhere A. Communication satellite B. Repeater C. Relay station D. Transponder

Description : Designed to receive a signal from a transmitting station on the ground and retransmit it to a receiving station located elsewhere A. Communication satellite B. Repeater C. Relay station D. Transponder

Last Answer : A. Communication satellite

The mode of communication that involves a single source transmitting information to a large number of receivers simultaneously, is called (A) Group Communication (B) Mass Communication (C) Intrapersonal Communication (D) Interpersonal Communication

Description : The mode of communication that involves a single source transmitting information to a large number of receivers simultaneously, is called (A) Group Communication (B) Mass Communication (C) Intrapersonal Communication (D) Interpersonal Communication

Last Answer : (B) Mass Communication

In RF and microwave system, what instrument is used to measure the incidental and reflected signals?

Description : In RF and microwave system, what instrument is used to measure the incidental and reflected signals?

Last Answer : reflectometer

By the transition of inner shell electrons in heavy atoms, high energy photons are emitted which are a) gamma rays b) X-rays c) radio waves d) photon rays

Description : By the transition of inner shell electrons in heavy atoms, high energy photons are emitted which are a) gamma rays b) X-rays c) radio waves d) photon rays

Last Answer : b) X-rays

The layer of the atmosphere in which Radio Waves are reflected back is called- (1) Ionosphere (2) Troposphere (3) Stratosphere (4) Exosphere

Description : The layer of the atmosphere in which Radio Waves are reflected back is called- (1) Ionosphere (2) Troposphere (3) Stratosphere (4) Exosphere

Last Answer : (1) Ionosphere Explanation: The Radio waves are reflected back to Earth in the Ionosphere which is an electrically charged layer of the upper atmosphere. This process is used to communicate beyond the horizon, atintercontinental distances, mostly in the shortwave frequency bands.

Radio waves are reflected back from which layer of the Earth's atmosphere?

Description : Radio waves are reflected back from which layer of the Earth's atmosphere?

Last Answer : Ionosphere

What factor determines whether a radio wave is reflected or refracted by the ionosphere?

Description : What factor determines whether a radio wave is reflected or refracted by the ionosphere?

Last Answer : Thickness of ionized layer.

What is one of the major reasons for the fading of radio waves which have been reflected from a surface?

Description : What is one of the major reasons for the fading of radio waves which have been reflected from a surface?

Last Answer : Shifting in the phase relationships of the wave.

Bats detect the obstacles in their path by receiving the reflected ______. a) infrasonic waves c) ultrasonic waves b) electromagnetic waves d)radio waves

Description : Bats detect the obstacles in their path by receiving the reflected ______. a) infrasonic waves c) ultrasonic waves b) electromagnetic waves d)radio waves

Last Answer : c) ultrasonic waves

The layer of the atmosphere in which Radio Waves are reflected back is called ; (1) Ionosphere (2) Troposphere (3) Stratosphere(4) Exosphere

Description : The layer of the atmosphere in which Radio Waves are reflected back is called ; (1) Ionosphere (2) Troposphere (3) Stratosphere(4) Exosphere

Last Answer : Ionosphere

Wireless communication is reflected back to the earth’s surface by the which zone?

Description : Wireless communication is reflected back to the earth’s surface by the which zone?

Last Answer : Ionsphere

Consider the following statements: 1. In a direct-to-home (DTH) system, the viewer dish antenna picks up signals from the satellite directly. 2. Cable operators receive signal from the satellite on large community dish antennas and then transmit to the viewers’ sets. Which of the above statements is/are correct? (a) Only 1 (b) Only 2 (c) Both 1 and 2 (d) Neither 1 nor 2

Description : Consider the following statements: 1. In a direct-to-home (DTH) system, the viewer dish antenna picks up signals from the satellite directly. 2. Cable operators receive signal from the satellite on large community dish antennas and ... ? (a) Only 1 (b) Only 2 (c) Both 1 and 2 (d) Neither 1 nor 2

Last Answer : Ans:(c)

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

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

Which of the following antennas receive signals in the horizontal plane equality well from all directions? A. Horizontal Hertz antenna B. Vertical loop antenna C. Vertical Yagi antenna D. A vertical antenna which is a quarter-wavelength long

Description : Which of the following antennas receive signals in the horizontal plane equality well from all directions? A. Horizontal Hertz antenna B. Vertical loop antenna C. Vertical Yagi antenna D. A vertical antenna which is a quarter-wavelength long

Last Answer : D. A vertical antenna which is a quarter-wavelength long

Collects very weak signals from a broadcast satellite A. Helical antenna B. Satellite dish C. LNA D. TWT

Description : Collects very weak signals from a broadcast satellite A. Helical antenna B. Satellite dish C. LNA D. TWT

Last Answer : B. Satellite dish

Which of the following antennas receives signals equally well from all directions in a horizontal plane? A. Hetz antenna B. Vertical Marconi antenna C. Yagi antenna D. Helical antenna

Description : Which of the following antennas receives signals equally well from all directions in a horizontal plane? A. Hetz antenna B. Vertical Marconi antenna C. Yagi antenna D. Helical antenna

Last Answer : B. Vertical Marconi antenna

______ is the first component of any MATV system to received broadcast signals. A. Receiver B. Antenna C. Filter D. Transmitter

Description : ______ is the first component of any MATV system to received broadcast signals. A. Receiver B. Antenna C. Filter D. Transmitter

Last Answer : B. Antenna

ECE Board Exam March 1996 What is the purpose of the receiver’s squelch circuit? A. To overcome fluctuations in the level the RF signal arriving at the receiver antenna B. To prevent fluctuations in the AGC bias level C. To reduce the receiver’s sensitivity to all incoming signals D. To prevent amplified noise from reaching the loudspeaker during the absence of an incoming signal

Description : ECE Board Exam March 1996 What is the purpose of the receiver's squelch circuit? A. To overcome fluctuations in the level the RF signal arriving at the receiver antenna B. To prevent ... signals D. To prevent amplified noise from reaching the loudspeaker during the absence of an incoming signal

Last Answer : D. To prevent amplified noise from reaching the loudspeaker during the absence of an incoming signal

Explain how modulation reduces height of antenna and avoid mixing of signals.

Description : Explain how modulation reduces height of antenna and avoid mixing of signals.

Last Answer : Modulation reduces antenna height: For the transmission of radio signals, the antenna height must be multiple of λ/4 ,where λ is the wavelength . λ = c /f where c : is the ... will occupy different slots in the frequency domain (different channels). Thus, modulation avoids mixing of signals.

The device that converts digital signals to analog signals at the start of long distance transmissions is (1) peripheral (2) modem (3) telephone (4) antenna

Description : The device that converts digital signals to analog signals at the start of long distance transmissions is (1) peripheral (2) modem (3) telephone (4) antenna

Last Answer : modem

Choose the most appropriate statement (A) An antenna can radiate only HF signals

Description : Choose the most appropriate statement (A) An antenna can radiate only HF signals (B) An antenna can radiate and receive HF signals (C) An antenna can receive only HF signals (D) An antenna can receive and transmit simultaneously HF signals

Last Answer : Choose the most appropriate statement (A) An antenna can radiate only HF signals (B) An antenna can radiate and receive HF signals (C) An antenna can receive only HF signals (D) An antenna can receive and transmit simultaneously HF signals