Communication Systems, Popular Questions: Karnataka Class 12-science PHYSICS, Physics Puc Ii (part 2)

abhinuj28... asked a question

Subject: Physics, asked on on 11/1/11

what is modulation? what is its need.

Akash Sharma asked a question

Subject: Physics, asked on on 6/10/17

Q.30. Mass is distributed uniformly over a thin square plate. If two end point of a diagonal are (- 2, 0) and (2, 2), what are the coordinates of centre of mass of plate?
(1) (2, 1)
(2) (2, 2)
(3) (1, 0)
(4) (0, 1)

Anandita asked a question

Subject: Physics, asked on on 22/2/11

What is meant by grating element?

Sky asked a question

Subject: Physics, asked on on 18/1/18

Solve this:
Two identical bodies are made of a material for which the heat capacity increase with temperature. One of these is at 100^o C, while the other one is 0^o C. If the two bodies are b ought into contact then, assuming no heat loss, the final common temperature is :
(1) less than 50^oC but greater than 0^o C (2) 0^o C
(3) 50^o C (4) more than 50^o C

Abhiram Sasidhar asked a question

Subject: Physics, asked on on 21/2/13

why skywave not used in the transmission of tv signals?

Akash Sharma asked a question

Subject: Physics, asked on on 25/10/17

Q.29. A force F is applied at the top of a ring of mass M and radius R placed on a rough horizontal surface as shown in figure. Friction is sufficient to prevent slipping. The friction force acting on the ring is -

(1)

\frac{F}{2}

towards right
(2)

\frac{F}{3}

towards left
(3)

\frac{2 F}{3}

towards right
(4) Zero

Karan asked a question

Subject: Physics, asked on on 4/3/14

What is the difference between point to point and broadcast communication modes. Give one example

Akash Sharma asked a question

Subject: Physics, asked on on 6/10/17

Q.3. The moment of inertia of a square lamina about the perpendicular axis through its centre of mass is 20 kg-

m^{2}

. Then, its moment of inertia about an axis touching its side and in the plane of the lamina will be :
(1) 10 kg-

m^{2}

(2) 30 kg-

m^{2}

(3) 40 kg-

m^{2}

(4) 25 kg-

m^{2}

Alka Vijay asked a question

Subject: Physics, asked on on 24/2/11

define sky wave propogation

Akash Sharma asked a question

Subject: Physics, asked on on 26/2/18

Solve this:
Q). A sphere of radius 25 cm and mass 1 kg is hung by a string of negligible mass and length 40 cm, then tension in the string is :

(1) 10.81 N
(2) 18.4 N
(3) 10 N
(4) 8 N

Mirza Khalit Afzal Beg asked a question

Subject: Physics, asked on on 24/6/12

why ar microwaves used in RADAR?

Akash Sharma asked a question

Subject: Physics, asked on on 5/10/17

Q 29

29. A ring takes time t₁ and t₂ for sliding down and rolling down an inclined plane of length L respectively for reaching the bottom. The ratio of t₁ and t₂ is :-

(1) \sqrt{2} : 1 (2) 1 : \sqrt{2} (3) 1 : 2 (4) 2 : 1

Utkarsh asked a question

Subject: Physics, asked on on 25/1/19

Please solve it

Akash Sharma asked a question

Subject: Physics, asked on on 5/10/17

Q.56. When a sphere of moment of inertia I rolls down on an inclined plane the percentage of total energy which is rotational, is approximately
(1) 28 %
(2) 72 %
(3) 100 %
(4) none of these

Amrutha asked a question

Subject: Physics, asked on on 12/11/12

when modulation index is kept less than 1 distortion dosent occur.......how and why???? plxzzzzzzz reply briefly........nd fastly.......

Sky asked a question

Subject: Physics, asked on on 18/1/18

Solve this:
Q.32. If a carved black utensil is heated to high temperature and then brought in dark then :
(1) Both utensil and its carving will shine
(2) Only carving will shine
(3) Only utensil will shine
(4) None of the utensil and carving will shine

Aditi Singh asked a question

Subject: Physics, asked on on 22/11/14

draw a block diagram of a simple amplitude modulation.explain briefly,how amplitude modulationis achieved.

Armin Kalita asked a question

Subject: Physics, asked on on 1/3/12

Explain why high frequency carrier waves are needed for effective transmission of signals?

Supratick Ghosh asked a question

Subject: Physics, asked on on 16/8/18

A rocket is launched upward from the earth surface whose velocity time graph shown in the figure.Then maximum height attained by rocket

anupgoyaledurtc... asked a question

Subject: Physics, asked on on 6/12/10

what is square law device? what is the function of this?

Please suggest me any me hurry up!

i am wating your reply?

Akash Sharma asked a question

Subject: Physics, asked on on 18/9/17

Q The only force F acting on a 2 kg body moves along x-axis varies as shown in the figure. The velocity of the body along positive x-axis at x=0 is 4m/s. The kinetic energy of the body at x=3 m is:-
1) 4 J
2)8 J

3)12 J
4)16 J

Jayshree asked a question

Subject: Physics, asked on on 13/1/13

State two factors by which the range of TV signal can be increased??

Akash Sharma asked a question

Subject: Physics, asked on on 12/10/17

Q.34. In the figure shown find out the distance Of centre of mass of a system of a uniform circular plate of
radius 3 R from O in which a hole of radius R is cut whose centre is at 2R distance from centre of large circular plate.

(1) R/4
(2) R/5
(3) R/2
(4) none of these

Ria Sarkar asked a question

Subject: Physics, asked on on 20/1/13

why do we need to modulate the frequency?

Akash Sharma asked a question

Subject: Physics, asked on on 26/9/17

Q.11. Two rings having same radius and mass are placed such that their centres are at a common point and their planes are perpendicular to each other. Find the moment of inertia of the system about an axis passing through the centre and perpendicular to the plane of one of the rings. (M = mass of each ring and R = radius).

sumitkanwar148... asked a question

Subject: Physics, asked on on 23/12/11

what are the limitations of amplitude modulation?

Renju & 1 other asked a question

Subject: Physics, asked on on 11/11/12

explain detection of amplitude modulated wave

Aishwarya S asked a question

Subject: Physics, asked on on 2/3/15

what % of am wave power is carried by side bands for m=1

Nikhil Chaudhari asked a question

Subject: Physics, asked on on 3/3/13

What is meant by detection of modulated carrier wave? Explain briefly steps for detection?

Akash Sharma asked a question

Subject: Physics, asked on on 10/9/17

Answer 4 please

Q. 4 A block of mass 15 kg is resting on a rough inclined plane as shown in figure. The block is tied up by a horizontal string having a tension of 50 N. Calculate the coefficient of friction between the block and the inclined plane.

Anand Verma asked a question

Subject: Physics, asked on on 26/10/13

what is ground wave propagation

Tanima asked a question

Subject: Physics, asked on on 9/7/18

In the following figure ,if tension in the string AB is 51N ,then tension in the string BC will be?

Jignesh Agarkar asked a question

Subject: Physics, asked on on 2/3/13

Which mode of propagation is used by short wave broadcast services having frequency range from a few MHz upto 30MHz? Expain diagrammatically how long distance communication can be achieved by this mode.Why is there an upper limit to frequency of waves used in this mode?

Sir plz..give the answer fast!!!!

Abhee & 1 other asked a question

Subject: Physics, asked on on 4/3/16

write two factors justifying the need of modulating a signal.

Arshan Ahmad asked a question

Subject: Physics, asked on on 26/4/18

The height above the ground of a child on a swing varies from 1 meter at lowest point. The maximum speed (in m/s ) of the child is approximately?
(A)-3. (B)-5. (C)-7. (D)-10.

asonianj2011... asked a question

Subject: Physics, asked on on 20/1/12

Why do we use manganine wire in potentiometer?

Sky asked a question

Subject: Physics, asked on on 18/1/18

Solve this:

Q. Two spheres of radii in the ratio 1 : 2 and densities in the ratio 2: 1 and of same specific heat, are heated to same temperature and left in the same surrounding. Their rate of falling temperature will be in the ratio:

(1) 2 : 1 (2) 1 : 1 (3) 1 : 2 (4) 1 : 4

Ck asked a question

Subject: Physics, asked on on 25/10/12

what is square law device?

Anmol asked a question

Subject: Physics, asked on on 20/12/17

Q13

Q13. A solid sphere of mass m and radius R is rolling without slipping on a rough horizontal surface with angular acceleration

α

. Centre of mass of sphere lies at a distance

\frac{R}{\sqrt{2}}

from the centre of sphere. Find the normal force applied by sphere on the surface at an instant when line joining centre of mass of sphere and centre of sphere makes an angle 45° with vertical and angular velocity of sphere at this instant is

ω

.

(A) mg + \frac{mR}{2} (α - ω^{2}) (B) mg - \frac{mR}{2} (α + ω^{2}) (C) mg + \frac{mR}{2} (α - ω^{2}) (D) mg + \frac{mR}{2} (α + ω^{2})

V S Jey Govind asked a question

Subject: Physics, asked on on 14/2/12

Sir, Why moon cannot be used as a communication satellite?

Hardee Shah asked a question

Subject: Physics, asked on on 7/2/17

A particle moves with a constant speed v along a circular path of radius r and completes the circle in time T. What is the acceleration of the particle?

Jaikhlang Brahma asked a question

Subject: Physics, asked on on 30/10/12

I need to prepare project on Communication System ...can someone help me on it

It is based on the CBSE....and i need it for submission for the partial fullfilment for the requirement for studies in Physics 10+2.

please help me select toic or to prepare.

your help is heartly welcome at: thomasofjnv@gmail.com

before 06 november, 2012.

Krishna Vamsi asked a question

Subject: Physics, asked on on 27/10/17

Block A of mass m rests on the plank B of mass 3 m which is free to slide on a frictionless horizontal surface. The coefficient of friction between the block and plank is 0.2. If a horizontal force of magnitude 2 mg is applied to the plank B, the acceleration of A relative to the plank and relative to the ground respectively are:

(1)

0, \frac{g}{2}

(2)

0, \frac{2 g}{3}

(3)

\frac{3 g}{5}, \frac{g}{5}

(4)

\frac{2 g}{5}, \frac{g}{5}

Anand Verma asked a question

Subject: Physics, asked on on 26/10/13

What is space wave propagation?

Virajas Yadav asked a question

Subject: Physics, asked on on 11/6/19

find the Center of mass os the system consisting of a square plate and a semicircular disc. given that mass per unit area is M which is same for both the objects.

Liya Sara Joy asked a question

Subject: Physics, asked on on 16/1/12

explain about downlink and uplink????

Nikita D asked a question

Subject: Physics, asked on on 22/6/14

The block diagram of AM transmitter and AM receiver

Akshay asked a question

Subject: Physics, asked on on 21/3/12

what is the necessity of modulation?

Shiva Pillai asked a question

Subject: Physics, asked on on 2/3/16

What is meant by critical frequency for sky wave propagation? Write an expression for the critical frequency in terms of the maximum electron density of the ionosphere. What is the range of variation of frequency for this critical frequency?

Hasna .p asked a question

Subject: Physics, asked on on 18/3/11

1) What is 'square law device'?What is it's use?
2)What is 'bandpass filter centred'?
3)What is the purpose of 'IF stage'?

rajesh2011 asked a question

Subject: Physics, asked on on 19/2/14

examples of sky wave propagation,ground wave rpopagation

tonyneeranakunnel... asked a question

Subject: Physics, asked on on 19/1/11

why is an FM signal less susceptible to noise than AM signal ?

Jiyarul Haque asked a question

Subject: Physics, asked on on 25/12/17

What should be the height of a transmitting antenna for a TV telecast to cover a radius of 128 km?

Meer Abdus Samad asked a question

Subject: Physics, asked on on 4/3/16

how are sidebands produced ?

Anurag asked a question

Subject: Physics, asked on on 29/5/16

in an amplitude modulated wave for audio frequency of 500cycles/second,the appropriate carrier frequency will be

Supriya Anand asked a question

Subject: Physics, asked on on 2/3/14

A TV tower has a height of 100m. How much population is covered by the TV broadcast if the average population density around the tower is 1000 persons per sq km?

Vipasha Sandip Patil asked a question

Subject: Physics, asked on on 2/4/18

Q. The block shown here is in equilibrium. The acceleration of the block just after the string burns is ng/3, find the value of n

Arun Mohan A M & 3 others asked a question

Subject: Physics, asked on on 31/10/14

What is amplitude modulation?

Vanitha Lakshmi asked a question

Subject: Physics, asked on on 15/8/19

Two equal masses m1 and m2 moving along the same straight line with velocity +3 m/s and -5 m/s respectively collide elastically. Their velocities after the collision will be respectively

Shiva Pillai asked a question

Subject: Physics, asked on on 2/3/16

Derive an expression for covering range of TV transmission tower

Soumya N asked a question

Subject: Physics, asked on on 14/4/18

Solve this:
Q.7. In optical communication system operating at 1200 nm, only 2 % of the source frequency is available for TV transmission having a bandwidth of 5 MHz. The number of TV channels that can transmitted is
(a) 2 million
(b) 10 million
(c) 0.1 million
(d) 1 million

anjalip19... asked a question

Subject: Physics, asked on on 18/1/13

an audio signal is not transmitted directly by converting it into an electromagnetic wave of same frequency.give 2 reasons.

Subhadip asked a question

Subject: Physics, asked on on 8/10/17

Please solve this
Q.21. A loaded 20,000 kg coal wagon is moving on a linear track with a 8 m/s. Suddenly 8000 kg of coal is dropped out of wagon. The final speed of the wagon is
(1) 6 m

s^{- 1}

(2) 8 m

s^{- 1}

(3)

\frac{40}{3}

m/s
(4)

\frac{20}{3}

m/s

Dadhichi asked a question

Subject: Physics, asked on on 5/3/13

KINDLY PROVIDE THE SOLUTION OF PHYSICS CLASS 12 SET 55/3 OF BOARD 2013 SOON?

Pankaj asked a question

Subject: Physics, asked on on 30/5/16

in an amplitude modulated wave for audio frequency of 500 cycles/second, the appropriate carrier frequency will be

Tuhinaa Nanda asked a question

Subject: Physics, asked on on 14/11/12

pls explain modulation and demodulation???/

Shruti Mishra asked a question

Subject: Physics, asked on on 30/4/18

A particle performing SHM undergoes displacement of A/2 in one second. At t=0 the particle was located at either extreme position or mean position. The time period of SHM can be : (consider all possible cases)

Shivani Sharma asked a question

Subject: Physics, asked on on 24/2/12

X and Y are two parallel plate capacitor having same area of plate and same separation b/w the plates X has air b/w the plates andY has dielectric of dielectric constant k=4

Ayman asked a question

Subject: Physics, asked on on 7/11/15

With a block diagram explain elements of communication system.

Sneha Pai asked a question

Subject: Physics, asked on on 9/12/13

draw a plot of variation of ' amplitude ' versus 'w ' for an amplitude modulated wave. hence explain the need for keeping the broadcast frequencies sufficiently spaced out ?

Sholong asked a question

Subject: Physics, asked on on 12/2/18

Solve this:
Q.11. What percentage of power of AM wave is carried by the side bands for modulation index m = 1 ?

Sanjay & 1 other asked a question

Subject: Physics, asked on on 20/6/15

what is html?explain in detail?

Prasanta Ghosh asked a question

Subject: Physics, asked on on 6/8/18

A rope of mass m and length L slides down through a inclined plane of inclination @ .what is the tension in the midpoint of the rope.co?

Prithvi Raj asked a question

Subject: Physics, asked on on 9/12/14

define frequency modulation ? write the advantages of frequency modulation over amplitude modulation ?

Ashish Chandel asked a question

Subject: Physics, asked on on 14/1/17

what is the function of a band pass filter used in a modulator for obtaining AM signal

Sanjita Prajapati asked a question

Subject: Physics, asked on on 2/1/12

what does line of sight communication means???

Rajbhanu Shukla asked a question

Subject: Physics, asked on on 12/5/19

The spring has a force constant 5000N/m. The pulley is light and smooth. The spring and string are light. The suspended block A is of mass 10kg. If the block is slightly displaced vertically down from its equilibrium position and released. Find the period of its vertical oscillation.

Saloni Gupta asked a question

Subject: Physics, asked on on 16/2/13

Why do long distance radio broadcasts use shortwave bands?

Akash Sharma asked a question

Subject: Physics, asked on on 25/10/17

Q.4. What should be the minimum coefficient of static friction between the plane and the cylinder, for the cylinder not to slip on an inclined plane -
(1)

\frac{1}{3} \tan θ

(2)

\frac{1}{3} \sin θ

(3)

\frac{2}{3} \tan θ

(4)

\frac{2}{3} \sin θ

Anand Verma asked a question

Subject: Physics, asked on on 26/10/13

What is sky wave propagation ?

Ravi Kant asked a question

Subject: Physics, asked on on 10/4/13

A diode detector is used to detect an amplitude modulated wave of 60% modulation by using a condenser of capacity 250 pico farad in parallel with a load resistance 100 kilo ohm. Find the maximum modulated frequency which could be detected by it

Ismail K asked a question

Subject: Physics, asked on on 2/2/14

A message signal of frequency 10kHz and peak voltage 10 V is used to modulate a carrier of frequency 1 MHz and peak voltage of 20V.Determine

a) Modulation Index

b) the side bands produced