Define the following terms: (i) Polarization (ii) Antenna gain (iii)Antenna resistance (iv)Directivity

1 Answer

i) Polarization:-

It is defined as the direction of electric field vector in the EM wave radiated by the transmitting antenna.

ii) Antenna Gain:-

Antenna gain is defined as the ratio of the power density radiated in a particular direction to the power density radiated to the same point by the reference antenna.

It is mathematically given by,

image

Where

P = power density at some point with the given antenna

Pref = power density at same point with the reference antenna

iii)Antenna Resistance:- Radiation resistance is the AC antenna resistance and is equal to the ratio of the power radiated by the antenna to the square of the current at its feed point. It is

given by,

image
Iv) Directivity :-
It is the maximum directive gain which is obtained in only one direction in which the radiation is maximum.
That is directivity = Max. directive gain
Like 0 like Dislike 0 dislike

Related questions

Description : Define the following terms related to antennas; (i) Antenna resistance (ii) Directivity (iii) Antenna gain (iv) Power density

Answer : Antenna Resistance - The resistance of an antenna has two components: 1. Its radiation resistance due to conversion of power into electromagnetic waves 2. The resistance due to actual losses in the ... the transmitter power divided by the surface area of a sphere (4πR2) at that distance.

Description : Describe with respect to antenna (i) radiation pattern (ii) directive gain (iii) power gam (iv) polarization

Answer : (i) Radiation pattern:-A graph or diagram which tells us about the manner in which an antenna radiates more power in different directions is known as the radiation patteren of antenna.  ( ... as the direction of the electric vector in the electromagnetic wave radiated by the transmitting antenna. 

Description : An antenna has a radiation resistance of 72 Ω a loss resistance of 8 Ω and a power gain of 16. Find efficiency and directivity.

Answer : An antenna has a radiation resistance of 72 Ω a loss resistance of 8 Ω and a power gain of 16. Find efficiency and directivity.

Description : Write one application of following antenna i. Rectangular antenna ii. Dish antenna iii. Yagi-Uda antenna iv. Horn antenna 

Answer : i. Rectangular antenna is used in direction finding in portable recievers. ii. Dish antenna is used to transmit and receive signal from satellite. iii. Yagi-Uda antenna is used in HF and VHF range as a TV receiving antenna. iv. Horn antenna is used in satellite tracking.

Description : Draw radiation pattern for following antenna i) Yagi-Uda antenna ii) Loop antenna iii) Dish antenna iv) Horn antenna

Answer : Type of antenna Radiation Patteren  Yagi-Uda antenna Loop antenna Dish antenna Horn antenna 

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

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.

Description : Compare PAM, PWM, and PPM on the basis of i. Variable characteristics ii. Bandwidth iii. Information contained in iv. Transmitted power

Answer : Compare PAM, PWM, and PPM on the basis of i. Variable characteristics ii. Bandwidth iii. Information contained in iv. Transmitted power

Description : a) For a transmission line, Find SWR and reflection coefficient R if, i. There is no reflected voltage. ii. Reflected voltage and incident voltage is equal. iii. If reflected voltage=20V and incident voltage=10V. iv. If reflected voltage=10V and incident voltage =20V.

Answer : reflection coefficient R=Vr/Vi i. There is no reflected voltage. i.e,Vr=0 R=0 SWR= 1+R/1-R=1 ii. Reflected voltage and incident voltage is equal. Vr=Vi; R=1 SWR= 1+R/1-R=1+1/1-1=infinity iii. If reflected ... and incident voltage =20V. Vr=10 and Vi=20 R=10/20=0.5 SWR= 1+R/1-R=1+.5/1-.5=3 

Description : Differentiate between AM and FM on the basis of: (i) Definition (ii) Bandwidth (iii) Modulation Index (iv) Application

Answer : Compare AM and FM on the basis of i)Definition ii)Bandwidth iii) Wave propogation iv)Number of sidebands

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

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 : Define the following terms: i) Level line ii) Bench Mark iii) Change point iv) Profile levelling

Answer : i) Level line - It is line lying in a level surface; it is therefore, normal to the plumb line at all points. ii) Bench Mark - These are fixed points or marks of known RL determined with ... the centerline of a proposed ditch or road or the centerline of a natural feature such as a stream bed.

Description : Define the following terms: (i) Level surface {ii) Datum line (iii) Reduced level (iv) Axis of telescope

Answer : i)Level Surface : Any surface is parallel to mean spheroidal surface of earth is said to be a level surface. The water surface of still lake is also considered to be level surface. ii) ... an imaginary line passing through the optical Centre of object glass and optical Centre of the eye piece.

Description : Define the following terms: (i) Data abstraction (ii) Class (iii) Dynamic binding (iv) Polymorphism

Answer : (i) Data abstraction: Abstraction refers to the act of representing essential features without including the background details or explanation. Data abstraction is the process of defining a data type, often ... more than one form at different instances depending on the type or number of arguments. 

Description : Define the following terms : (i) absorptivity (ii) reflectivity (iii) transmissivity (iv) emissivity

Answer : Absorptivity: It is the fraction of total incident radiation which is absorbed by a body. Reflectivity: It is the fraction of total incident radiation which is reflected by a body.  Transmissivity: It ... total emissive power of a body to emissive power of a black body at the same temperature. 

Description : Define following terms (i) Kinematic link (ii) Kinematic pair (iii) Kinematic chain (iv) Mechanism (v) Machine (vi) Inversion

Answer : (i) Kinematic link: Each part of a machine, which moves relative to some other part, is known as a kinematic link.  (ii) Kinematic pair: The two links or elements of a machine, ... obtaining different mechanisms by fixing different links in a kinematic chain is known as inversion of the mechanism.

Description : Define following terms: i) Economic span ii) Afflux iii) Waterway iv) Free board

Answer : i) Economic span: The span for which the total cost of the bridge is minimum is known as economical span of a bridge. ii) Afflux: It is the rise in water surface caused due to the obstruction ... , if any, and the lowest point on the underside of the bridge super structure is called free board.

Description : Define the following terms with respect to protective relays i) Relay time ii) Reset current iii) Plug setting multiplier and iv) Time setting multiplier

Answer : 1) Relay Time: The time interval between occurrence of fault and closure of relay contacts.  2) Reset Current: The value of current below which the relay resets and comes back to ... The adjustment arrangement provided for setting the operation time of relay is known as Time setting multiplier. 

Description : Define following terms used in A.C. circuits : (i) Cycle (ii) Rms value (iii) Phase difference (iv) Average value

Answer : (i) Cycle:   A complete set of variation of an alternating quantity which is repeated at regular interval of time is called as a cycle. OR  Each repetition of an alternating quantity ... charge as is transferred by the alternating current during the same time under the same conditions. 

Description : Define following terms related to logic families : (i) Noise Margin (ii) FAN-OUT (iii) Propagation delay (iv) Power dissipation

Answer : i) Noise immunity is measured in terms of noise margin. High state Noise margin = VNH = VOH(min) - VIH(min) Low state Noise margin = VNL = VIL(max) - VOL(max) i) The fan-out is defined as the ... logical 0 state (HIGH to LOW) iii) Average power dissipation is defined as PD(avg) = ICC(avg) * VCC

Description : Define the following terms : (i) Base Station (ii) Control Channel (iii) Mobile Station (iv) Page 

Answer : i) Base Station: - A fixed station in a mobile radio system used for radio communication with mobile stations. Base stations are located at the center or on the edge of a coverage region ... the page throughout the service area using base stations which broadcast the page on a radio carrier.

Description : Define the following terms related to tariff: (i) Connected load (ii) Unit consumed (iii) Fixed charges (iv) Electricity Tax 

Answer : (i) Connected load  It is the sum of the power ratings (Watts or kW or MW) of all devices and machines existing (installed) in the premises of consumer. It is used to decide the ... a percentage of the total electricity bill which includes all amounts that go to the electricity supply agency. 

Description : Define the following terms: i) Magnetic flux density, ii) Reluctance, iii) Magneto-motive force, iv) Permeance.

Answer : (i) Magnetic flux density (B): It is the magnetic flux per unit area measured at right angles to the flux path. (Its unit is weber/m2 or tesla).  (ii) Reluctance: It is the ... flux to set up through it and it is reciprocal of reluctance. Permeance = 1/ Reluctance. Unit: weber/ampere.

Description : Draw the structure and state applications of: i) Ferrite loop (rod) antenna ii) Horn antenna

Answer : Horn antenna: Application:- i) Used at microwave frequency. ii) Used in satellite tracking.  Ferrite loop antenna: Application:- In Am radio receiver to receive MW and SW band signals. In FM radio receiver

Description : Draw the radiation pattern for Dipole antenna: (i) Half wave dipole (ii) Folded dipole.

Answer : The radiation pattern for Half wave dipole antenna The radiation pattern for Folded dipole antenna.

Description : Define: i) Q point ii) DC loadline iii) Need of biasing iv) Current gain

Answer : i) Q point: It is the point on the load line which represents the dc current through a transistor (ICQ) and the voltage across it (VCEQ), when no ac signal is applied.  ii) DC load line: The ... region is as desired.  iv) Current Gain: It is a ratio of output current to input current.

Description : Define the terms i) Fore Bearing, ii) Open traverse, iii) Closing error, iv) Reduced bearing

Answer : i) Fore bearing : The bearing observed in the direction of progress of survey in clockwise manner is called fore bearing  ii) Open traverse : When the first and last survey lines does ... north or south direction in clockwise or anticlockwise manner is known as reduced or quadrantal bearing. 

Description : Define the terms related to a.c. supply with waveform : i) Instantaneous value ii) Time period iii) Amplitude iv) Phase difference. 

Answer : i) Instantaneous value: The instantaneous value is the value of an alternating quantity (it may ac voltage or ac current or ac power) at a particular instant of time in the cycle .  OR  ... difference: Phase difference is the difference in phase angle between two sinusoids or phasors. 

Description : Define the terms: (i) Lamp efficiency (ii) Luminous flux (iii) Luminaire (iv) Colour Rendering Index. 

Answer : i) Lamp efficiency or luminous efficiency: It is the ratio of luminous flux emitted by a lamp to the power consumed by the lamp. It is a reflection of efficiency of energy conservation ... of surfaces illuminated by a given source compare to those of the same surface under reference illuminant.

Description : Define the terms: i) Tariff ii) Fuel surcharge iii) Electricity Duty iv) Connected load

Answer : i) Tariff: The rate at which a consumer is charged for the consumption of electricity is called as tariff. OR The amount of money framed by the supplier for the supply of electrical energy ... is the total wattage of all appliances which are used by the consumer on his sanctioned connection. 

Description : Define the terms : i) Node ii) Branch iii) Loop iv) Mesh

Answer : i) Node:  A point or junction where two or more elements of the network are connected together is called as node.  ii) Branch: A part of an electric network which lies between two junctions ... path (same as loop) in an electric circuit. OR A loop that does not contain any other loop inside

Description : Define the terms: i) Hardness ii) Toughness iii) Brazing iv) Machinability

Answer : i) Hardness:- Hardness is the property of metal possessed by a material which enables it to resist penetration or abrasion or scratching by other material. Diamond is the hardest of known materials.  ... can be easily cut by cutting tools to produce a desired shape & surface finish on its surface

Description : Define with respect to FET:- (i) Static drain resistance (ii) Dynamic resistance (iii) Trans conductance (iv) Pinch-off voltage

Answer : (i) Static drain resistance- It is the ratio of drain source voltage (ΔVDS) to the drain current (ID) at constant gate-source voltage. It can be expressed as, Rd = (VDS)/(ID) at ... of charge carrier and the value of drain current reaches its constant saturation value is called pinch off voltage.

Description : Identify type of BJT configuration having following features : (i) BJT configuration having the least current gain. (ii) KIT configuration called as voltage follower. (iii) BJT ... configuration suitable for voltage amplification. (vi) BJT configuration having the least output impedance.  

Answer : (i) BJT configuration having the least current gain : Common Base Configuration  (ii) KIT configuration called as voltage follower: Common Collector Configuration  (iii) BJT ... Emitter Configuration  (vi) BJT configuration having the least output impedance: Common Collector Configuration

Description : State the types of electromagnetic polarization? Define any one of it.

Answer : Transverse electromagnetic wave:- The polarization of a plane EM wave is simply the orientation of the electric field vector with respect to the surface (i.e. looking at the horizon) If ... the field strength varies with change in polarization the wave is said to have an elliptical polarization 

Description : Define electromagnetic wave and polarization.

Answer : Electromagnetic wave:-An electromagnetic wave such as light consists of a coupled oscillating electric field and magnetic field which are always perpendicular; by convention Polarization:-polarization" of electromagnetic waves refers to the direction of the electric field.

Description : Describe the following terms: (i) Keyword (ii) Identifier (iii) Variable (iv) Constant

Answer : (i) Keyword: Keywords are special words in C programming which have their own predefined meaning. The functions and meanings of these words cannot be altered. Some keywords in C Programming are if, while, ... or a string literal. There are enumeration constants as well. Example: 121 234 3.14 

Description : Classify the soil according to IS Classification and explain the meaning of following terms i) GW ii) SP iii) ML iv) SM-ML

Answer : As per IS classification soil is broadly divided into three divisions: 1. Coarse grained soil: In these soils, more than half the total material by mass is larger than 75 micron IS ... medium compressibility. iv) SM-ML - boundary classification between coarse grained and fine grained soils. 

Description : Suggest the degree of workability in terms of slump for the following: i) Pavements using pavers ii) Canal lining iii) Heavily reinforced sections iv) In-situ piling

Answer : Degree of workability in terms of slump for the following: i) Pavements using pavers: 25-75 mm ii) Canal lining: 70-80 mm iii) Heavily reinforced sections: 50-100 mm iv) In-situ piling: 100-150 mm

Description : Explain the meaning of following terms: i) MCB ii) Socket outlet iii) Neutral iv) Fuse-link

Answer : i) MCB:  Miniature circuit breaker operates automatically at the time of fault or over load. And it is used for the protection of electrical installation. They are available from 0.5 A to 100 Amps. ... melts automatically at the time of fault or over load. Fuse must be replaced after the fault.

Description : State the significance of following terms : i) Hydrology ii) Surface run-off iii) Evaporation iv) Precipitation

Answer : (i) Hydrology: It may be defined as the science which deals with the depletion and replenishment of water resources. Hydrology deals with the occurrence and distribution of water over and under earth's ... types:  a) Liquid precipitation (Rainfall)  b) Solid precipitation (Snow, Hail) 

Description : In a FM system, the maximum deviation is 75KHz. Find bandwidth for modulating frequency i. fm=500Hz ii. fm=5KHz iii. fm=10KHz Draw conclusion for bandwidth of FM from answer.

Answer : Given deviation∆=75kHz i) fm=500Hz bandwidth B.W=2(∆+fm)  =2(75k+500)=151kHz  ii). fm=5KHz bandwidth B.W=2(∆+fm)  =2(75k+5k)=160KHz iii) fm=10KHz bandwidth B.W=2(∆+fm)  =2(75k+10k)=170KHz As the modulating frequency increases bandwidth also increases.

Description : Differentiate between positive and negative feedback on the basis of . (i) overall phase shift (ii) voltage gain (iii) stability (iv) applications 

Answer : Compare positive feedback and negative feedback on the basis of: (i) Gain (ii) Bandwidth (iii) Phase shift (iv) Stability

Description : Compare BJT common base configuration with common collector configuration on the basis of (i) Current gain (ii) Voltage gain (iii) Input impedance (iv) Output impedance

Answer : Parameter Common Base Common Collector Current gain Low (About 1) High (1+β) Voltage gain High 1  Input impedance  Low High Output impedance High Low

Description : State any two applications of each for the following types of electrical heating : (i) Direct resistance heating(ii) Indirect induction heating (iii) Direct.arc heating (iv) Dielectric heating

Answer : (i) Direct resistance heating:- 1. This type of heating used for industrial purpose 2. Salt bath heating: This utilized for the purpose of carbonizing, tempering, quenching and hardening of steel tools 3. ... purpose. 14)In foundry for heating of sand, core, which are used in molding processes.

Description : Name the method used to measure following resistances:- (i) Low resistance (ii) Medium resistance (iii) Insulation resistance (iv) Earth resistance.

Answer : Following are the methods used to measure resistances:-  (i) Low resistance: 1.Voltmeter-Ammeter Method 2. Kelvin's Double bridge Method  (ii) Medium resistance: 1.Voltmeter-Ammeter Method 2. ... of Charge Method  (iv) Earth resistance : 1. Fall of Potential Method 2. Earth tester

Description : Defines the terms : i) Survey Station ii) Survey Line iii)Offset iv)Triangulation 

Answer : i) Survey Station : It is the point on ground from which various observations are taken around it. ii) Survey Line : It is the straight line joining two successive survey stations ... iv)Triangulation : The frame work consist of number of connected well conditional triangle is called Triangulation.

Description : Define: (i) Image frequency and (ii) Double spotting

Answer : i)Image frequency:- Image Frequency is defined as the signal frequency plus twice the intermediate frequency. It is denoted as fsi = fs+2fi Where, fs = Signal Frequency fi =intermediate frequency ... It is due to the poor front end selectivity i.e., inadequate image frequency rejection.

Description : Define and explain the term beam width related to antenna with a sketch.

Answer : Definition: The beam width of an antenna is described as the angles created by comparing the half power point (3dB) on the main radiation lobe to its maximum power point. As an example the beam width ... max voltage at center of lobe (these point are known as half power points.) Sketch-  

Description : Define the following terms:  (i) Drug (ii) Dosage forms (iii) Excipients

Answer : (i) Drug- A chemical agent intended for use in the diagnosis, mitigation, treatment, cure or prevention of disease in man or in other animals. (ii) Dosage forms- Dosage form is a ... along with Active Pharmaceutical Ingredients make up the dosage forms. Eg. suspending agent ,emulsifying agent etc.

Description : Define the following special types of concretes with its one use. i) Vacuum concrete ii) Fiber reinforced concrete iii) High performance concrete iv) Self-compacting concrete

Answer : The uses of special types of concretes are as follows.  i) Vacuum concrete: It is the concrete in which entrained air and excess water form concrete mix is taken out from vacuum pump, ... . large bridge and machine foundations iii. Pumped concrete for floors and slabs. iv. Pre-stressed concrete

← Prev Question Next Question →
Ask a Question
Choose topic