IMPORTANCE OF COMMUNICATION IN ARMY

Ques 1.   Why is efficient signal communication important for the Defence Forces?

Ans -    (a) Communicating between deployed troops and commanders.

            (b) Convey the details of enemy troop movements and their activities.

            (c) To change the mode of battle activities.

            (d) To implement emergency instruction in battle field.

            (e) To convey specific orders in terrain and snow bound area.

            (f) For effective operational changes in battle field.

            (g) To acquire and decipher the information and misinformation of enemy.

(h) To prepare the troops for further operational activities.

(j) To assess grounds level effect of operational activities.

(k) To improve infrastructure facilities in battle field.

(l) To carry out secure and effective communications with precaution and privacy.

(m) Communication supply of food and evacuation of casualties.



Ques 1.    What are the various methods of communication?

Ans -      (a) Sign Language

              (b) Voice Medium

  (c) Written script

              (d) Runners and message bearers

              (e) Line and cable

  (f) Wireless




Ques 1.  What are the advantages and disadvantages of Line communication?

Ans - These are as under : -


             (a) Reliable and practically free from electrical interference.

             (b) Relatively secure.

             (c ) Number of circuits and message carrying capacity is more but limited only by 

             availability of material and manpower.


(a) Vulnerable to physical interference and enemy interception along the entire length

of the route.

            (b) Takes time to construct.

            (c ) Inflexible once it is laid.

            (d) Expensive in men and material.

Ques 2 - What are the advantages and disadvantages of Net Radio?

Ans - Advantages.

            (a) Is vulnerable only at terminal and is therefore reasonably protected from enemy

             action except by a direct hit. 

(b) Is very flexible, can be rapidly re-arranged in the event of regrouping.

             (c ) Is rapid in establishing communication.

            (d) Can work on the move although range obtained will be much less than               

            when stationary.

            (e) Is economical in personnel and equipment.


            (a) Is inherently insecure and susceptible to enemy interception which necessitates

            the use of codes and ciphers with a consequent delay in clearing traffic and

            overall increase in operating personnel.

(b) Net radio being inherently insecure demands a considerable degree of security consciousness on the part of the users. This means adherence to standard procedure and security codes.

Ques 3.  What are the advantages and disadvantages of Radio Relay?

Ans - Advantages

             (a) Replace line with considerable economy of manpower and stores.

 (b) It can be operated over area where for reasons of ground or enemy activity use of line 

 may not be possible.

             (c ) Provides greater flexibility than line.

             (d) Quick to set up and move except in mountainous country.

             (e) Is vulnerable physically only at terminal.

(f) By its ability to employ multichannel equipment radio relay provides more teleprinter circuits over one link than can normally be provided over the average field cable. Thus it has much greater traffic handling capacity.


(a) Liable to interception and hence insecure. Has relatively greater security than net radio, depending upon the siting and direction of the beams.

(b) Liable to interference from enemy jamming although not as much as in the case of net radio.

(c) Terrain between stations must be reasonable suitable to get a ‘quasi optical path’, this presents difficulty in siting.

(d) Location of terminal and intermediate stations may not suit tactical layout and may, therefore, create additional protection requirements.

(e) Can not work on the move.

(f) Slightly more expensive in men and material than in the case of net radio.

(g) Needs critical siting.


                                                     COMMUNICATION MEDIA

Ques 1 - What are the various transmission lines?

Ans -       (a) Parallel Wire type

               (b) Coaxial type

               (c ) Wave Guide type

Ques 2.    What are the various types of propagation of waves and explain each in brief?

Ans -    (a) Ground Wave Propagation. Used for long and medium waves, limited range is

             30 Kms.

(b) Sky Wave Propagation. Used for HF range up to 30 MHz communication, range is 100 km to 1000 Kms. These make use of ionosphere layer existing to a height of 150 -200 kms from the surface of earth.

            (c ) Space Wave Propagation. The propagation of VHF and UHF frequency takes place

            in straight lines. The range is limited by curvature of earth and so distance between two

            neighboring station is approx 50 Kms.

           (d) Tropospheric Scatter Propagation. Also known as tropo scatter or fwd scatter

           propagation, extended height up to 8-10 Kms from the surface of earth.



Ques 1.    What are the special feature and facilities available in Radio Set ANPRC-25?

Ans -    (a) It is a portable set.

            (b) It has RT communication facilities.

            (c) Can be used on ground and man pack.

            (d) Facilities of remote operating and re- broadcasting is available.

(e) Power supply can be increased with booster unit to increase the communication range.

             (f) Protection from Heat and Moisture.

             (g) VHF is pre-tuned.

             (h) Suitable for Para Dropping.

             (j) Compatible with RS VA and VA Mk II and VC.

             (k) Range will be doubled when it is used with GPA.

             (l) Can be used in all type of geographical areas.

Ques 2.   What is the weight and frequency range of Radio set ANPRC -25?

Ans -   (a) Weight          

                       (i) Radio Set - 6.10 Kg.

                       (ii) Battery - 1.60 Kg.

                       (iii) Accessories - 3.08 Kg.

                       (iv) Complete Station - 10.78 Kg.

(b) Frequency Range

(i) Frequency range of this set is 30 MHz to 75.95 MHz which is fixed with two bands.

                                    (aa) Band I - 30 MHz to 52.95 MHz

                                    (ab) Band II - 53 MHz to 75.95 MHz

(ii) Its frequency range is connected with 920 channels. Channel spacing from one channel to another channel is 50 KHz.

Ques 3.   What is communication range and power supply of Radio set ANPRC -25?

Ans -    (a) Communication Range

                       (i) With antenna AT 892 - 8 Km.

                       (ii) With Antenna AT 271 - 8 Km.

                       (iii) With booster Unit - 25 Km

                       (iv) With GPA with Booster - Range becomes double.

(b) Power Supply Consumption

Battery Dry HT/LT 15/3 V IA. Life of this battery is in the ratio of 1:9 for 20 hrs, in which transmission can be done for one hour and message can be receive for 9 hrs.




Ques 1 - What are the facilities available in RADIO SET GP 338 MOTOROLA?

Ans -    (a) It is portable and light in weight.

            (b) Can be operated easily.

            (c) It can be operated in VHF/UHF and 2 way simplex mode.

             (d) 128 channel of this radio set can be preset into 8 zone.

            (e) 16 channels can be preset into single zone.

            (f) Frequency of this radio set can be programmed in 25 KHz channel space with the range

            of 12.5 to 20 KHz.

(g) Option of selective call facilities available.

(h) Call alert can be given to receiver station.

(j) Can select required zone.

(k) Start/stop facilities of scan operation available.

(l) Add/Delete from scan list facilities available.

(m) Menu key facilities are available.

            (n) Provision of receiving signal strength indicator (RSSI) are available.

(o) Provision of name/Tone Tagging facility available.

(p) Provision of talk around indicator facility available.

(q) Provision of 14 character Alfa numerical display LCD facility available.

(r) Provision of clock/reminder alarm facility available.

(s) Audible alert tone indicator is provided.

(t) Seven programmable buttons are provided.

(u) Facility of emergency siren top button is provided.

(v) Battery gauge indicator facility is provided.

(w) Accessory connectors is provided with radio set.

(x) Provision of DTMF key pad ( Duel Tone Mute Freq).

(y) Clock and alarm is provided.

(z) Time out timer facility is provided.

(aa) Provision of battery saver.

(ab) Power level can be adjusted.

(ac) Provision of MDC-1200 signalling encode/decode (Motorola digital code).

Ques 2.    What is the weight and frequency range of Radio Set GP 338 Motorola?

Ans -   (a) Weight and Measure

                          (i) Weight and measure of this radio set is as follows:-

                          (ii) Dimension with NI MH high cap battery - 137 x 57.5 x 37.5 mm.

                          (iii ) Wight with NI MH high cap battery - 420 gms.

(b) Frequency Range Frequency of this radio set is as under:-

                         (i) 136 MHz to 174 MHz on VHF mode.

                         (ii) 403 MHz to 470 MHz on UHF mode.

Ques 3.   What is the communication range and name of power supply of Radio Set GP 338 Motorola?

Ans -    (a) Communication Range Communication range of this radio set is 4 to 5 Km and 20 to 40 Km with repeater.

(b) Power Supply Power supply can be provided to this radio set by the following batteries.

                         (i) Ni MH high cap 7.2 volt.

(ii) Ni MH ultra high cap 7.2 volt.

(iii) Ni Cd High cap FM 7.2 volt.        

                         (iv) Ni Cd High cap 7.2 volt.

                         (v) Lithium 7.2 volt.



Ques 1.   What are the basic functions of telephone sets 'L', 'F', 'J', 'EE', '8B'?

Ans - (a) It works on magneto signalling.

(b) Calling is done by magneto.

(c) CB calling and clearing is done.

(d) It provides speech communication.

(e) It works in all weather conditions

Ques 2.  What are the facilities if Switch Board Telephone 15 Lines?

Ans - (a) 15 Lines can be provided.

(b) Can work with either magneto, CB, CBS or auto exchanges.

(c ) Has got both internal and external ringer.

(d) Two exchanges can be linked up to provide 30 line facility.

(e) A lamp indicator has been provided to warn the operator about an in coming call.

(f) A ringing visual indicator has been provided.

(g) Facility exists for night alarm.

(h) Apart from the dry battery, power source can be provided by secondary battery also.

(j) Lighting facility for the switch board is provided by means of specially designed lighting unit.

Ques 3.  What are the advantages and functions of Telephone Set 5A/5B?

Ans - The telephone set Field 5A/5B has the following functions and advantages:-

(a) Facility exists for installing a autodial and hooking with an auto exchange.

(b) Facility for line test exists.

(c ) A device has been installed in the micro phone for noise cancellation.

(d) In H position the range of the telephone is increased considerably.

(e) Facility exists on the both 5 A/5 B for remote operating.

(f) Made of superior magneto and can function with CB/CBS exchanges.

Ques 4 - What is the [power supply and consumption of the Telephone Set 5A/5B?

Ans - It is powered by 2 X 1.5 Volt No 3 cells or 3 V external batteries and the power consumption of set 5 A is 20 mA and set 5 B is 15 mA. It can receive and sent signal waves with a bell due to generator

Ques 5 -What is the main difference between Telephone set 5 A and 5 B?

Ans - Telephone Set 5 A                                                 Telephone Set 5 B

               (a) Small in size                                                Large in size

               (b) Light in weight                                              Heavier

              (c) Auto call can be attached                             Auto call can not be attached

              (d) Bell is tubular type                                        Bell is Gong type

              (e) CB Loop resistance is 200, 250, 300.           CB Loop resistance is from 200 to 350

              (f) TRL switch exists                                          TRL switch does not exists

              (g) Threaded type of line terminal                      Push type line terminal

Ques 5 - What are the important phrases used while operating the exchange?

Ans -     (a)       'Number please , Sir'.

             (b)       'You want number______, Sir'.

             (c )       'Sorry , Sir Number is engaged , Sir'.

             (d)       'I will ring you back , Sir'.

             (e)       'Call for you from_______'Speak up, please'.

             (f)        'Have you finished . Sir'.

                                                                    SECTION -8


Ques 1.   What are the latest trends in communication?

Ans - These are as under : -

(a) Tropo-scatter

(b) Modem

(c) Fax

(d) Telex

(e) Satellite

(f) Optic fiber communications

(g) Computer system

(h) Internet

(i) Cell phone

(j) Multimedia

(k) Videophone

Ques 2 - Name various types of satellites?

Ans -     (a) Weather Satellite.

             (b) Scientific Satellite.

             (c ) Communication Satellite.

             (d) Navigational Satellite

             (e) Military Satellite.

Ques 3.    What are the advantages and disadvantages of optic fiber communication?

Ans.      (a) Advantages

                        (i) It has wide band width carrying different types of info from low speed voice

                        signal to high speed computer data.

                        (ii) Less power requirement.

                        (iii) Small cable size.

                        (iv) No repeater station required.

                         (v) No electromagnetic interference.

            (b) Disadvantages

                        (i) Jointing problem.

                        (ii) Channel dropping not possible.

                        (iii) More expensive.

Ques 4 - What are the advantages and disadvantages of Computer system?

Ans -     (a) Advantages

                         (i) Speed of process and calculations.

(ii) Accuracy of process and calculation once the programme is proved.

(iii) Persistence - It will continue on the same job until the end, always working in the same way, each and every day.

                        (iv) Mass storage of data.

                        (v) The ability to handle large volume of data.

             (b) Disadvantages

                        (i) Data loss if machine malfunctions.

                         (ii) Back up hard data still required to be maintained.

(iii) Constant power source is required.

Ques 5. What are the advantages of cell phone?

Ans -    (a) More subscriber and traffic capability.

            (b) No perceptible difference between mobile and fixed subscribers.

            (c ) Better quality of service.

(d) Miniaturization using very large scale integration (VLSI ) technology which enables ever decreasing size and weight of the hand set.

           (e) Higher speed of data exchange.

           (f) Can be used in an integrated mode with computer network.

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