Recent questions tagged ch15

A T.V transmission town antenna is at a height of 20 m . How much service area can it cover if the receiving antenna at ground level

asked Sep 30, 2016 by meena.p

1 answer

Compute the LC product of a tuned amplifier circuit which requires a carrier wave of $1\;MHz$ for amplitude modulation

asked Sep 30, 2016 by meena.p

1 answer

The maximum amplitude of an A.M wave is found to be $3\;v$ What is modulation index?

asked Sep 30, 2016 by meena.p

1 answer

Two waves A and B frequencies $2\;MHz$ and $3MHz$ respectively are beamed in the same direction for communication via sky wave .Which one of there is likely to travel longer distance in the ionosphere before suffering total internal reflection ?

asked Sep 30, 2016 by meena.p

2 answers

Would sky waves be suitable for transmission of TV signal of $60\; MHZ$ frequency ?

asked Sep 30, 2016 by meena.p

1 answer

Which of the following :- Would produce digital signals

asked Sep 30, 2016 by meena.p

1 answer

Which of the following :- Would produce analog signals

asked Sep 30, 2016 by meena.p

1 answer

A TV transmission tower has a height of $240 \;m$ signal broad cast from this will be received by LOS Communication at a distance of (assume the radius of earth to be $6.4 \times 10^6 \;m)$

asked Sep 30, 2016 by meena.p

1 answer

An audio signal of $15\;KHz$ , frequency can not be transmitted over long distances without modulation because

asked Sep 30, 2016 by meena.p

1 answer

Identify the mathematical expression for amplitude modulated wave

asked Sep 30, 2016 by meena.p

1 answer

A basic communication system consists of A)transmitter B) Information Source C) User of information D) Channel E) receiver Choose the correct sequence in which these are arranged in a basic communication system

asked Sep 29, 2016 by meena.p

1 answer

A made voice after modulation - transmission sounds like that of a female to the receiver . The problem is due to

asked Sep 29, 2016 by meena.p

1 answer

A message signal of frequency $w_m$ is super posed on a carrier wave of frequency $w_c$ to get an amplitude modulated wave (Am). The frequency of the AM wave will be

asked Sep 29, 2016 by meena.p

1 answer

A speech signal of $3\;kHz$ is used to modulate a carrier signal of frequency $1\;MHz$ , using amplitude modulation . The frequencies of the side band will be

asked Sep 29, 2016 by meena.p

1 answer

A 1 Kw signal is transmitted using as communication channel which provides attention at the rate of $-2 dB$ per km. If the communication channel has a total length of 5 km , the power of the signal received is [ gain in $dB = 10 log \bigg( \Large\frac{P_0}{P_c}\bigg) ]$

asked Sep 29, 2016 by meena.p

1 answer

A $100\;m$ antenna is mounted on a $500\;m$ tall building . The complex can become transmission tower for waves with $\lambda$

asked Sep 29, 2016 by meena.p

1 answer

Three waves A,B and C of frequencies $1600\;kHz, 5 MHz$ and $60\;MHz$ respectively are to be transmitted from one place to another . Which of the following is the most appropriate mode of communication ?

asked Sep 29, 2016 by meena.p

1 answer

For an amplitude modulated wave , the maximum amplitude is found to be 10 v while the minimum amplitude is found to be $2v$.What would be the value of $\mu $ if the minimum amplitude is zero volt ?

asked Sep 29, 2016 by meena.p

1 answer

For an amplitude modulated wave , the maximum amplitude is found to be 10 v while the minimum amplitude is found to be $2v$. Determine the modulation index $\mu$ .

asked Sep 29, 2016 by meena.p

1 answer

A modulatiy signal is a square wave as shown in the figure . The carrier wave is given . $c(t) = 2 \sin (8 \pi t) volt.$ Find modulation index.

asked Sep 29, 2016 by meena.p

1 answer

A carrier wave of Peak voltage $12\;v$ is used to transmit a message signal. What should be the peak voltage of the modulating signal in order to have a modulation index of $75\%$

asked Sep 28, 2016 by meena.p

1 answer

Is it necessary for a transmitting antenna to be at the same height on that of the receiving antenna for the line of sight communication ? A T.v transmitting antenna is $81 m$ tall.How much service area it can cover if the receiving antenna is at the ground level ?

asked Sep 28, 2016 by meena.p

1 answer

Digital signals (i) do not provide a continuous set of values (ii) represent values as discrete steps (iii) can utilize only binary system and (iv) can utilize decimal as well as binary system . which of the following options is true ?

asked Sep 28, 2016 by meena.p

1 answer

Frequencies in the UHF range normally propagate by means of

asked Sep 28, 2016 by meena.p

1 answer