Recent questions tagged easy

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

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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

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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

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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

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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

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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

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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

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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

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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

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Frequencies in the UHF range normally propagate by means of

asked Sep 28, 2016 by meena.p

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What is the peak value of $220\;v\;a.c$

asked Sep 28, 2016 by meena.p

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In an a.c circuit , there is no power consumption in an ideal inductor . why ?

asked Sep 28, 2016 by meena.p

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A resistor of resistance $100 \Omega$ is connected to an ac source. $E= (12 v) \sin (250 \pi s^{-1})t$ Find the energy dissipated as heat during $t=0$ to $t= 1.0\;ms$

asked Sep 28, 2016 by meena.p

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An electric motor operation on a $50\;v$ d.c supply draws a current of $12\;A$ . If the efficiency of the motor is $30\%$ , estimate the resistance of the motor .

asked Sep 28, 2016 by meena.p

1 answer

A generator develops am e.m.f of $120\;v$ and has a terminal potential difference of $115\;v$ when the as mature current is $25\;A$ What is the resistance of the as mature ?

asked Sep 28, 2016 by meena.p

1 answer

Can a capacitor be used instead of a choke coil in controlling a.c ?

asked Sep 28, 2016 by meena.p

1 answer

Why do we prefer a choke coil to a rheostat in controlling a.c ?

asked Sep 27, 2016 by meena.p

1 answer

Why are air cored chokes used for reduced high frequency a.c ?

asked Sep 27, 2016 by meena.p

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The calculate the current drawn by the prime of a transformer which steps down $200\;v$ to $20\;v$ to operate a device of resistance $20 \Omega$ the efficiency of the transformer to be $80\%$

asked Sep 27, 2016 by meena.p

1 answer

Raj bought two rolls of tape. The first roll had 11.8 metres of tape and the second roll had 19.5 metres of tape. How many metres of tape did Raj buy in all?

asked Sep 26, 2016 by balaji.thirumalai

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If the cost of milk is Rs. 14 per litre and I bought in 14.4 litres, how much did I have to pay?

asked Sep 26, 2016 by balaji.thirumalai

1 answer

Explain why the reactant offered by an inductor increased with increased frequency of an alternating voltage.

asked Sep 26, 2016 by meena.p

1 answer

Explain why the reactant provided by a capital to an alternating current decreases with increasing frequency .

asked Sep 26, 2016 by meena.p

1 answer

Both alternating current and direct current are measured in ampere. But how is the ampere defined defined for an alternating current .

asked Sep 26, 2016 by meena.p

1 answer

In LC circuit , is considered analogous to a harmonically oscillating spring block system, which energy of LC circuit would be analogous to potential energy and which one analogous to kinetic energy ?

asked Sep 22, 2016 by meena.p

1 answer

The line that draws power supply to your house from street has

asked Sep 22, 2016 by meena.p

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Electrical energy is transmitted over large distance at high alternating voltage . Which of the following statement are correct ?

asked Sep 22, 2016 by meena.p

1 answer

In an alternating current circuit consisting of elements in series, the current increases on increasing the frequency of supply . Which of the following elements are likely to continue the circuit ?

asked Sep 22, 2016 by meena.p

1 answer

As the frequency of an ac circuit increase, the current first increase and then decrease . What combination of circuit elements is most likely to comprise the circuit ?

asked Sep 22, 2016 by meena.p

1 answer

The output of a step down transformer is measured to be $24\;v$ when connected to a 12 walt light bulb. The value of the peak current is

asked Sep 22, 2016 by meena.p

1 answer

A small town with a demand of $800\;kw$ of electric power at $220\;v$ is situated $15\;km$ away from an electric plant generating power at $440\;v$. The resistance of the two line wires carrying power is $0.5\;\Omega$ per km. The town gets power from the lines through a $40,000-220\;v$ Step down transformation. Neglect leaked losses . hence explain why high voltage transmission is preferred .

asked Sep 21, 2016 by meena.p

1 answer

A small town with a demand of $800\;kw$ of electric power at $220\;v$ is situated $15\;km$ away from an electric plant generating power at $440\;v$. The resistance of the two line wires carrying power is $0.5\;\Omega$ per km. The town gets power from the lines through a $4000-220\;v$ Step down transformation at a substation in the town .Characterize the step up transformer at the plant

asked Sep 21, 2016 by meena.p

1 answer

A small town with a demand of $800\;kw$ of electric power at $220\;v$ is situated $15\;km$ away from an electric plant generating power at $440\;v$. The resistance of the two line wires carrying power is $0.5\;\Omega$ per km. The town gets power from the lines through a $4000-220\;v$ Step down transformation at a substation in the town . How much power must the plant supply , assuming there is negligible power loss due to leakage ?

asked Sep 21, 2016 by meena.p

1 answer

A small town with a demand of $800\;kw$ of electric power at $220\;v$ is situated $15\;km$ away from an electric plant generating power at $440\;v$. The resistance of the two line wires carrying power is $0.5\;\Omega$ per km. The town gets power from the lines through a $4000-220\;v$ Step down transformation at a substation in the town . Estimate the power loss in the form of heat

asked Sep 21, 2016 by meena.p

1 answer

A power transmission line feeds input power at $2300\;v$ to a step down transformer , with its primary winding's having $4000$ turns. What should be the number of turns in the secondary windings in order to get out put power at $230\;v$

asked Sep 20, 2016 by meena.p

1 answer

A capacitor is used in the primary circuit of an induction coil . Why ?

asked Sep 20, 2016 by meena.p

1 answer

In any a.c circuit is the applied instantaneous voltages equal to the algebraic sum of the instantaneous voltages across the series element of the circuit ? Is the same true for r.m.s voltage?

asked Sep 20, 2016 by meena.p

1 answer

A circuit containing a $80\;mH$ inductor and a $60 \mu F$ capacitor in series is connected to a $230\;v,50\;Hz$ supply . The resistance in the circuit is negligible. What is the total average power absorbed by the circuit ?

asked Sep 19, 2016 by meena.p

1 answer

A circuit containing a $80\;mH$ inductor and a $60 \mu F$ capacitor in series is connected to a $230\;v,50\;Hz$ supply . The resistance in the circuit is negligible. What is the average power transferred to capacitor ?

asked Sep 16, 2016 by meena.p

1 answer

A circuit containing a $80\;mH$ inductor and a $60 \mu F$ capacitor in series is connected to a $230\;v,50\;Hz$ supply . The resistance in the circuit is negligible. What is the average power transferred to inductor ?

asked Sep 16, 2016 by meena.p

1 answer

How does an inductor behave in a d.c circuit after the steady state ?

asked Sep 15, 2016 by meena.p

1 answer

A series LCR circuit connected to a variable frequency $230\;v$ Source has $L= 5.0\;H,c=80 \mu F,R= 40 \Omega$ as shown in the figure. obtain the impedance of the circuit and amplitude of current at the resonating frequency.

asked Sep 12, 2016 by meena.p

1 answer

A series LCR circuit connected to a variable frequency $230\;v$ Source has $L= 5.0\;H,c=80 \mu F,R= 40 \Omega$ as shown in the figure

asked Sep 12, 2016 by meena.p

1 answer

A series LCR circuit with $R= 20\; \Omega, L= 1.5\;H$ and $C= 35\;\mu F$ is connected to a variable frequency 200 v a.c supply. when the frequency of the supply equals the natural frequency of the circuit, what is the average power transferred to the circuit in one complete cycle ?

asked Sep 9, 2016 by meena.p

1 answer

A changed $30 \;\mu F$ capacitor is connected to a $27\;mH$ inductor. Suppose the initial charge on the capacitor is $6\;mc$ what is the total energy stored in the capacitor initially ? What is the total energy at later time ?

asked Sep 9, 2016 by meena.p

1 answer

Which of the following frequency will be suitable for beyond the horizon communication using sky waves.

asked Sep 9, 2016 by meena.p

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