# Communication Systems Questions and Answers

Physics
Communication Systems
Percentage error in the determination of g is If velocity of light in vacuum 3 x 108 m s acceleration due to gravity 9 81 m s2 and density of mercury 13600 kgm be adopted as the fundamental units choose the correct option s a unit of mass is 1 05 x 1052 kg b unit of length is 9 17 x 10 5 m
Physics
Communication Systems
Find the rate of flow of glycerine of density 1 25 10 Kg m through the conical section of a pipe if the radii of its end are 0 1 m and 0 04 m and the pressure drop
Physics
Communication Systems
A microwave telephone link operating at the central frequency of 10 GHz has been established If 2 of this di is available for microwave communication channel then how many telephone channels can be simultaneously granted if each telephone is alloted a bandwidth of 10 KHz a 2 104 c 5 x 107 b 104 d 6 10 9 10 11
Physics
Communication Systems
A solid cylinder of mass m length I and area of cross section A is placed as shown in the figure If Young s modulus is Y then strain energy stored in the cylinder is A C 2 m g l 3AY 2 m g 1 7 A V B D m g 1 6AY m g 1 AY
Physics
Communication Systems
Two particles of masses 2 g and 36 g respectively are attached to two ends of a rigid light rod of length 1 9 m The centre of the mass of the system from 2 g particle is nearly at distance of 1 4 m 1 8 m 1 7 m 0 95 m
Physics
Communication Systems
Determine the output voltage of a differential amplifier for the input voltage of 300 micro volt and 240 micro volt The differential gain of the amplifier is 5000 and value of CMRR is a 100 b 100000
Physics
Communication Systems
A signal of frequency 20 kHz and peak voltage of 5 Volt is used to modulate a carrier wave of frequency 1 2 MHz and peak voltage 25 Volts Choose the correct statement A Modulation index 5 side frequency bands are at 1400 kHz and 1000 kHz B Modulation index 5 side frequency bands are at 21 2 kHz and 18 8 kHz C Modulation index 0 8 side frequency bands are D 180 kHz and 1220 kHz Modulation index 0 2 side frequency bands are at 1220 kHz and 1180 kHz
Physics
Communication Systems
Which among the following statements is correct regarding the dependence of voltage gain of an amplifier on the frequency of the signal A the signal does not depend upon frequency of Your Answer B signal increases with frequency of the decreases with frequency of the signal D with frequency of the signal initially constant and then decreases
Physics
Communication Systems
The figure shows a digital circuit constructed using negative edge triggered J K flip flops Assume a starting state of Q2Q Q0 000 This state will repeat after how many number of the cycles of the CLK 1 Jo Qo Clock clock 1 Ko Qo J clock 1 K Q1 Q J clock 1 K Q2 Q
Physics
Communication Systems
Let x t be a periodic signal with time period T Let y t x t to x t to for some to The Fourier Series coefficients of y t are denoted by bk If bk 0 for all odd k then to can be equal to 1 2 3 4 T 8 T 4 T 2 2T
Physics
Communication Systems
Question 2 In Figure 1 shown below how much stronger is the signal from transmitter A at the car than the signal from transmitter B if dA is six times as large as dB if the distances between the car and the transmitters are over 100 m Show intermediate steps and details transmitter A da da transmitter B
Physics
Communication Systems
Maximum amplitude of amplitude modulated wave is 12 volt and minimum amplitude is 4 volt If frequency of carrier wave is 1000 KHz and frequencies of side bands are 998 KHz and 1002 KHz then a Modulation index is 60 b Modulation index is 33 c Frequency of the modulating signal is 4 KHz d Frequency of the modulating signal is 2 KHz
Physics
Communication Systems
A body of mass m 1 8 kg is placed on an inclined plane of inclination a 37 with the horizontal It is attached to the top of the inclined plane with a string which is parallel to the inclined plane if the inclined plane is moved with a horizontal acceleration a What is the value of a in m s if the body pushes the slope with a Friction is absent force of 3mg 4 everywhere a m 37
Physics
Communication Systems
alternative A B C D C D then select the correct Bis parallel to C D A is perpendicular to C component of Calong Acomponent of Dalong A component of Calong A component of Dalong
Physics
Communication Systems
The condition of a semiconductor diode can be determined quickly using A B a digital display meter DDM a curve tracer C both A and B CO
Physics
Communication Systems
From an elevated point A a stone is projected vertically upwards When the stone reaches a distance h below A its velocity is double of what it was at a height h above A The greatest height attained by the stone is h 2h b 3 3 5h 5h 4 3 a c
Physics
Communication Systems
Ex A 500 m light colored swimming pool is located in a normal suburban site where the measured wind speed at 10 m height is 3 m s The water temperature is 25 C the ambient air temperature is 17 C and relative humidity is 60 There are no swimmers in the pool the temperature of the make up water is 22 C and the solar irradiation on a horizontal surface for the day is 20 2 MJ m d How much energy must the solar system supply Q to the pool to keep its temperature to 25 C
Physics
Communication Systems
y ABC B C A B INTO CANONICAL FORM IS 1 y m 0 1 4 2 y Em 0 1 7 3 y m 1 4 7 4 v Em 0 1 4 7
Physics
Communication Systems
Q4 For static system as shown in figure below if k 50 N mm m m 0 25 for the blocks m and m tensions T1 28 35N spring elongation 5 mm and the force F1 m cose m sin 0 Find the inclination angle Tension in other wire and the mass of blocks By using the Grammar method www T2 m2 3 T1 ml 0
Physics
Communication Systems
4 R To find the resistance of a galvanometer by the half deflection method the following circuit is used with resistances R 9970 2 R 30 2 and R3 0 The deflection in the galvanometer is 107 2 the deflection changed to d 2 The d With R3 galvanometer resistance is approximately 1 107 S2 3 107 20 2 1372 4 77 S HH 20 R G R3 2
Physics
Communication Systems
in the figure Then it will follow the following path The magnetic field is directed into the paper y 0 0 0 0 x A It will continue to move along positive axis B It will move along a curved path bendin towards positive x axis C It will move along a curved path bendi towards negative y axis th alc
Physics
Communication Systems
8 A long capillary tube with both ends open is filled with water and set in vertical position The radius of the capillary is 0 1 cm and the surface tension of water is 70 dyne cm The length of the water column remaining in capillary tube will be the g 1000 cm s2 and density of water 1 g cm 1 1 9 mm 3 2 8 mm 21 4 cm 4 2 8 cm
Physics
Communication Systems
A signal of 5 kHz frequency is amplitude modulated on a carrier wave of frequency 2 MHz The frequencies of the resultant signal is are 2015 1 2005 kHz and 1995 kHz 3 2000 kHz and 1995 kHz 2 2005 kHz 2000 kHz and 1995 kHz 4 2 MHz only
Physics
Communication Systems
kHz d 2522 kHz and 2498 kHz 30 An oscillator is producing FM waves o frequency 2 kHz with a variation of 10 kHz The modulation index is a 0 20 b 5 0 c 0 67 d 1 5
Physics
Communication Systems
The Young s modulus of a wire of length L and radius r is Y newton per square metre If the length is reduced to L 2 and radius to r 2 its Young s modulus will be Y 1 2 3 2Y 2 Y 4 4Y
Physics
Communication Systems
The K absorption edge of an unknown element is 0 167 Select the correct alternat A The unknown element will be Rhenium Z 75 B The unknown element will be Tungsten Z 74 C The average wavelength of the K D The average wavelength of the K line will be 0 0333 line will be 0 0222
Physics
Communication Systems
33 Which of the following options is correct for having a straight line motion represented by t s graph 0 D A B SI 8 1 The object moves with constantly increa sing velocity from O to A then it moves with constant velocity 2 Velocity of the object increases uniformly 3 Average velocity is zero A The graph shown is impossible
Physics
Communication Systems
Q 2 Aman s manners are a mirror in which he shows his portrait The quote highlights the importance of good manners in life Write an article for your school magazine on Good Manners You may use the following hints with your own ideas 8 marks Hints First step to success need for good manners makes life easy with politeness creates goodwill use words like thank you please sorry important words well mannered people liked by all Q 3 Anjali What is your plan for summer break Seema Seema I plan to a wada b my unt lives It is c few miles away Anjali Oh That sounds exciting When e a i visited ii visiting iii visit b i where ii who iii when c i a ii an iii the d i of ii from e i is ii was iii to iii are iv visits iv which iv little iv for iv were you leaving
Physics
Communication Systems
Limiting Reactant 1 A mixture containing 21 moles of F2 and 8 moles of S is allowed to react according to the reaction 3F2 SSF6 A What is the limiting reactant B How many moles of the excess reactant remain after all of the limiting reactant reacted completely
Physics
Communication Systems
4 Calculate the force between a particle with a charge of 0 0050 C and a particle with charge of 0 0030 C separated by a distance of 0 50 m
Physics
Communication Systems
Passage III The Carlingford Igneous Centre CIC was a site of volcanic activity in Ireland during the Ordovician Period that spanned 485 to 483 million years ago This type of volcanism is an example of bimodal volcanism in which both basalt and rhyolite magma are found in the core of the volcano This results in particularly violent eruptions Scientists studied the geological makeup of the CIC and discovered that this bimodal volcanism may be caused by the geological features of the rocks underneath the volcano Figure I illustrates a cross section of the rare earth element content of various CIC site Figure 2 shows the relationship between the niobium Nb and zirconium Zr content of crustal rocks found at the CIC site Volcanic activity can influence global climate and trigger cold events The injection of sulfur dioxide gas SO which is ultimately converted to sulfuric acid aerosol particles H SO scatters shortwave solar radiation and absorbs near infrared solar radiation and outgoing longwave terrestrial radiation This results in cooling of the troposphere and heating of the stratosphere Figure 3 shows the results of a study that examined the effect of erupting volcanoes on the number of cold events in Ireland 110 100 90 80 70 60 5 4 3 Set Three Key sites Figure 1 basalt rhyolite andesite trachyandesite 50 1 2 3 4 5 6 7 8 9 10 11 12 13 14 40 35 30 25 20 215 widd qN number of cold events 10 5 0 25 10 0 0 Oct Sep MS 100 X Nov Dec LC limestone 200 Jan Feb 300 Zr ppm Figure 2 fractionation Mar 12 contamination month Figure 3 Apr 400 total volcanic Key May non volcanic Jun 102 Jul 500 Aug 11 According to the information in Figure 1 as the cross sectional altitude of trachyandesite increases from Site 5 to Site 6 the amount of andesite A increases B remains the same C increases then decreases D decreases 12 According to Figure 3 as the number of volcanic events increases from 4 to 12 the overall number of cold events F increases only G decreases only H increases then decreases J decreases then increases dons 13 According to the information in Figure 3 does the total number of cold events depend on volcanic activity A Yes because as volcanic activity based cold events increase the total number of cold events increase B Yes because as volcanic activity based cold events increase the total number of cold events remain constant C No because as volcanic activity based cold events increase the total number of cold events increase No because as volcanic activity based cold events increase the total number of cold events remain constant D 14 According to Figure 1 as the cross sectional altitude of basalt decreases from Site 1 to Site 3 does the cross sectional altitude of rhyolite and andesite increase or decrease 04 F Rhyolite increases andesite increases G Rhyolite increases andesite decreases H Rhyolite decreases andesite increases J Rhyolite decreases andesite decreases 15 According to Figure 2 the relationship between Nb content and Zr content is best represented by A Nb 3 0 x Zr B Nb Zr 3 0 Zr C Nb 12 2 D Nb 12 2 x Zr END OF SET THE STOP DO NOT GO ON TO THE NEXT F UNTIL TOLD TO DO
Physics
Communication Systems
For this question you can use your textbook for details Please do not use direct sentences they won t make much sense here because you have to show your comprehension of what we ve been talking about in class and in the book Explain in 4 5 sentences how Ghana s fight for independence from Britain features ALL of the following patterns we have seen over and over in history when a nation is fighting for its independence from an imperialist country An existing nation s attitude about an imperialist country taking over The existing nation s actions to push out the imperialist country A power vacuum what it is and why it existed The most common type of government after a power vacuum make sure to name who filled the vacuum and what type of government they had
Physics
Communication Systems
When stars exhaust their core hydrogen and leave the main sequence they become giants During this stage what happens to their luminosity and surface temperature Select one A luminosity increases surface temperature increases OB luminosity increases surface temperature decreases OC luminosity decreases surface temperature increases OD luminosity decreases surface temperature decreases
Physics
Communication Systems
An FM radio station has a frequency of 96 7 MHz What is the corresponding wavelength to this radio station 0000 600 m 3 1 m 100 m 2 3 m
Physics
Communication Systems
ONE physics equation explained cell phone communication
Physics
Communication Systems
3 What does Congress do when it decides on appropriation
Physics
Communication Systems
Quinn is standing on the beach at the edge of the ocean looking straight ahead It is a clear day and Quinn can see so far that the earth starts to curve away She wonders how far she can see Quinn knows the radius of the Earth is approximately 3 959 miles and her eyes are 5 25 feet above the ground Which model can she use to help her figure out how far she can see in miles x Models are not drawn to scale 5 25 ft x mi 3 959 mi 5 25 ft x mi 3 959 mi Use this model to find how far Quinn can see out over the ocean There are 5 280 feet in a mile Round your answer to the nearest tenth
Physics
Communication Systems
A local FM radio station broadcasts at a frequency of 89 6 MHz Calculate the wavelength at which it is broadcasting Wavelength meter 1 MHz 106 s
Physics
Communication Systems
A local FM radio station broadcasts at a frequency of 90 7 MHz Calculate the energy of the frequency at which it is broadcasting Energy kJ photon 1 MHz 106 sec 1
Physics
Communication Systems
Work on an Abstract about Cell Phone Communication which should be a summary of what you want to explore this is a good way to guide yourselves to what you want to read about and absorb for your presentation The Abstract should be a paragraph or two which you should submit here
Physics
Communication Systems
Hunter S Thompson was a writer opposed to the Vietnam War He wrote a piece in the style of A Modest Proposal suggesting that he would use napalm to kill Vietnamese dogs and perhaps some people This text is an example of satire dramatic Irony manic sarcasm
Physics
Communication Systems
What happened in the speaker's and listener's brains when they communicated? You may answer with bullet points.
Physics
Communication Systems
If the frequency of the wave used by your favourite station is 91.6 Megahertz, what is the wavelength? Answer in units of m. Answer in units of m If the station is 55 km away, how long does it take for the radio waves to reach you from the station? Answer in units of seconds.
Physics
Communication Systems
How much work must you do to push a 12 kg block of steel across a steel table at a steady speed of 1.1 m/s for 4.4 s? The coefficient of kinetic friction for steel on steel is 0.60.
Physics
Communication Systems
Hunter S. Thompson was a writer opposed to the Vietnam War. He wrote a piece, in the style of A Modest Proposal, suggesting that he would use napalm to kill Vietnamese dogs and perhaps some people. This text is an example of satire dramatic Irony manic sarcasm None of the choices
Physics
Communication Systems
Using the equations below calculate the efficiency of a compact fluorescent light bulb if it produces 43 J of light energy, while 95 J of electrical energy is input. Type your answer below properly rounded to the tenths place! (No units! You'll select that in a question below!)
Physics
Communication Systems
The platter of the hard drive of a computer rotates at frequency f = 7200 rpm (rpm = revolutions per minute = rev/min) a. Calculate the angular velocity o (rad/s) of the platter. b. The reading head of the drive r = 3 cm (= 0.03 m) from the rotation axis. Calculate the linear speed v of the point on the platter just below it. c. If a single bit requires 0.5 µm of length along the direction of motion, how many bits per second can the writing head write when it is r = 3 cm from the axis?
Physics
Communication Systems
Where do meteors come from? A. They are the result of supernova. B. They are melted particles that fell from comets. C. They are debris from nuclear explosions in space. D. They came from asteroids that collided and tiny pieces chip off due to the collision.