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Correct choice is (d) sends incoming PACKETS out to all other TERMINALS connected to it

The explanation: Hubs are devices which are commonly used to connect SEGMENTS of a LAN. Its role is to SEND incoming packets out to all other terminals connected to it.

The correct choice is (c) sends incoming packets out to specific ports

Explanation: A switch CONNECTS different devices together on a computer NETWORK by using packet switching to receive, process and FORWARD data to the destination device.

The CORRECT choice is (b) to prevent one user from reading a record that another user is writing

To ELABORATE: In networks, record LOCKING is used to prevent the interference of one user in OTHERS WORK, it prevents the user from reading a record that another user is writing.

The correct answer is (a) True

For EXPLANATION: The term broadband refers to high speed Internet access. It is GENERALLY provided by cable TV companies. LAN connects several SYSTEMS to same network.

Correct answer is (b) Multitasking

Explanation: Multitasking is USED to RUN a client-server NETWORK.

The correct option is (a) PC with no DISK drives

To explain I WOULD SAY: A thin client is a dumb terminal. Dumb terminal is simply an output DEVICE that ACCEPTS data from CPU.

Right CHOICE is (C) 199.8 KHz

The best explanation: fm = fmax – fmin = 100KHz – 100Hz = 99.9KHz and Bandwidth = 2fm = 2 X 99.9 = 199.8 KHz.

The correct answer is (b) TRANSMISSION Control PROTOCOL

The explanation: TCP stands for Transmission Control Protocol. It is one of the MAIN protocols of the Internet. The entire suite is commonly referred to as TCP/IP. It helps in maintaining network relations which helps in exchanging of DATA.

Correct answer is (a) 5

The best explanation: TCP stands for Transmission Control Protocol. It is ONE of the main protocols of the INTERNET. It is originated in the INITIAL network implementation in which it complemented the Internet Protocol. The ENTIRE suite is commonly referred to as TCP/IP. It CONSISTS of 5 layers.

The CORRECT OPTION is (d) Interconnected Process

The BEST I can EXPLAIN: IP stands for Internet Protocol or it can be seen as a connection-less protocol.

The correct CHOICE is (b) depends on NUMBER of “hops” between nodes

For explanation I would say: Information is divided into small CHUNKS, called packets. The lifetime of a PACKET in an IP(Internet Protocol) network depends on the number of “hops” between nodes.

Correct answer is (B) False

The explanation: The STANDARD INTERNET address or URL is a 32-bit BINARY number. URL is a web resource that specifies its location on a computer network and a mechanism for RETRIEVING it.

Correct ANSWER is (b) translates words to NUMBERS

Explanation: DNS STANDS for Domain NAME Server. Domain Name Server is a host name to IP address translation service. It is a DISTRIBUTED database implemented in a hierarchy of name servers.DNS can translate words to numbers.

Correct answer is (a) a DNS

The explanation is: INTRANET USES internet technologies, but is insulated from the GLOBAL internet. An intranet CONNECTED to the internet is often PROTECTED by DNS.

Right choice is (b) radiated signal

Easy explanation: In ANTENNA impedance, impedance RELATED the voltage and current at the INPUT of the antenna. The real part of antenna impedance REPRESENTS power that is either radiated away or absorbed within the antenna and the imaginary part of antenna impedance represents power that is stored in the NEAR field of antenna.

The correct choice is (C) Hertz ANTENNA

The BEST explanation: The Hertz antenna is also known as half wave dipole antenna. It consists of two straight collinear conductors of EQUAL length separated by a small feeding gap.

The correct choice is (b) in two directions

To explain: As the name suggests, HALF WAVE DIPOLE is half wavelength long. This ANTENNA has the shortest resonant LENGTH that can be used for a resonant dipole. The field strength of a horizontally polarized half wave dipole antenna is strongest in two directions.

Correct option is (b) DIRECTIVITY

The explanation: When an ANTENNA radiates more energy in one direction than in other directions is called directivity. An antenna that radiates equally in all directions has effectively zero DIRECTIONALITY, and the directivity of this type of antenna should be 1 (or 0dB).

Right answer is (a) Effective Radiated POWER

Explanation: ERP STANDS for Effective Radiated Power. Effective Radiated Power (ERP) is always GIVEN with RESPECT to a certain direction.

Right ANSWER is (d) radio signals REFLECTING off the GROUND

For EXPLANATION: Radio signals that are reflecting BACK from the ground is responsible for ground effects in antenna.

The correct answer is (a) Faraday rotation

Explanation: GENERALLY for SATELLITE communication circular polarization is REQUIRED. The polarization RECEIVED by waves from satellite is changed by Faraday rotation.

The correct option is (c) cause SWR on the feed cable

The explanation: A non-resonant antenna have wider bandwidth as compared to the resonant antenna. It also has less SENSITIVITY than resonant antenna. Having less sensitivity means it can AMPLIFY weak SIGNALS EFFICIENTLY. A non-resonant antenna will cause SWR on the feed cable.

Right answer is (c) resistive

Explanation: In antenna IMPEDANCE, impedance related the VOLTAGE and CURRENT at the input of the antenna. The real part of antenna impedance represents power that is either radiated AWAY or absorbed within the antenna and the imaginary part of antenna impedance represents power that is stored in the NEAR field of antenna.The input impedance of a lossless antenna is purely resistive.

The correct option is (a) the number of lobes also increase

For explanation: An antenna is BASICALLY a TRANSDUCER that CONVERTS radio frequency fields into alternating current or vice versa. They can be used for both transmission and reception of radio signals. If the length of a LONG wire antenna is increased then the number of lobes also increases. The reception capability of an antenna also depends on it’s length.

The correct option is (a) mounted vertically

Explanation: A MONOPOLE antenna CONSISTS of a STRAIGHT rod shaped conductor. It is often mounted perpendicularly over some type of conductive surface, called a ground plane.

Correct CHOICE is (a) antenna’s radiation

For explanation I would say: Ground generally reflects the wave BACK that comes to it. It ALSO affects antenna by EFFECTING the radiation. The radiation intensity of an antenna is determined by comparing it with that of isotropic antenna.

Right answer is (b) between half POWER POINTS

The best I can explain: The ANGLE between the half power points of the main LOBE with RESPECT to the peak effective radiated power is called half power beamwidth. It is generally measured between half power points.

Correct OPTION is (a) 0 dB

Easy explanation: The front to BACK ratio means the ratio of power gain between the front and back of a directional ANTENNA. A half-wave dipolr antenna is one with length half of the WAVELENGTH. For a half-wave DIPOLE antenna, its value comes out to be 0dB.

The correct option is (a) amplitude of MODULATED WAVE

Easy EXPLANATION: AM wave is represented by Ac(1+xt) cos⁡ ωc t or Et cos⁡ ωc t, where xt is modulating signal, Ac is amplitude of carrier wave and Et is amplitude of AM wave.

The correct choice is (b) radiation resistance of the antenna

To explain I would SAY: An antenna is basically a transducer that converts radio frequency FIELDS into alternating current or VICE VERSA. They can be used for both transmission and reception of radio SIGNALS. Radiation resistance of the antenna is just a measure of radiation of energy from antenna.

Right answer is (a) slightly shorter than a half wavelength

The best explanation: The half wave dipole antenna is also known as Hertz antenna. It consists of TWO straight collinear conductors of EQUAL LENGTH separated by a SMALL feeding gap. The length of half wave dipole antenna is slightly shorter than half wavelength. It’s the SIMPLEST form of an antenna.

Correct answer is (a) Isotropic antenna

Explanation: Isotropic antenna is an ideal antenna that radiates its power UNIFORMLY in all DIRECTIONS. In practical, no isotropic antenna exists. It is often USED as a REFERENCE antenna for the antenna gain. Directive gain of a practical antenna is the ratio of the radiation intensity of the antenna to that of an isotropic antenna.

Correct option is (c) PROTECTION of personnel WORKING underneath

To explain I would say: If we consider the use of GROUND as a screen with ANTENNA then there is no chance that it is used for protection of personnel working underneath.

The correct OPTION is (b) Horn

To elaborate: A horn is an antenna that consists of a FLARING metal waveguide that is shaped like a horn. The horn shape helps to direct radio waves in a BEAM. It is WIDELY used as antennas at UHF.

Correct answer is (b) ACTS as an antenna ARRAY

To explain I would say: An ungrounded antenna near the ground acts as an antenna array. An antenna array is a combination of multiple antennae which function as a SINGLE antenna to perform the required task.

Right option is (d) a field strength METER

To explain I would say: Field strength meter is an instrument which is used to measure the electric field strength emanating from a transmitter. EIRP (EFFECTIVE Isotropic Radiated POWER) meter is used to measure the radiated power of an ANTENNA in a specific direction.

Correct OPTION is (C) collimated

The explanation: The radiated BEAM from a PARABOLIC “dish” transmitting antenna is collimated. Collimated light is that light whose rays are parallel due to which it disperse minimally as it PROPAGATES.

Correct answer is (d) PHASED, DRIVEN or parasitic

Explanation: An antenna array is a GROUP of multiple antenna which BEHAVES as a single antenna to perform the REQUIRED tasks. Arrays in the antenna can be phased, driven or parasitic.

The correct CHOICE is (B) False

Easy explanation: An antenna can be MATCHED to a feed line, also known as a transmission line, by using an LC network. But it can also be matched to feed line by a LOADING coil.

Right option is (a) Log Periodic Dipole Array

Best EXPLANATION: LPDA STANDS for Log Periodic Dipole Array. LPDA consists of a number of half-wave dipole driven elements which GRADUALLY increases in length.

The correct option is (a) Yagi

To elaborate: A Yagi-Uda antenna is a directional antenna consisting of many PARALLEL elements in a line. It consists of a single driven ELEMENT which is connected to the transmitter or RECEIVER with a TRANSMISSION line and also contains parasitic elements which are not connected to the transmitter or receiver. Thus, there are three or FOUR directors and one reflector.

Correct choice is (c) an anechoic CHAMBER

The best explanation: An antenna is basically a transducer that converts radio frequency fields into alternating CURRENT or vice versa. They can be used for both transmission and reception of radio signals. They are OFTEN tested in an anechoic chamber. An antenna is used to transmit high frequency waves and plays significant ROLE in the COMMUNICATION process.

Right choice is (c) rhombic antenna

Explanation: Non-resonant ANTENNAS are LIKE non-resonant transmission lines. Non-resonant transmission lines do not have standing waves. Hence they do not have any reflected wave and they have only FORWARD travelling wave. WHEREAS resonant antennae have standing wave patterns.

Correct answer is (B) log periodic

Easy explanation: A log periodic antenna is a multi-element, directional, antenna designed to OPERATE over a wide band of frequencies. WHEREAS, folded dipole and rest work over short band frequencies.