For identical total transmitted power, the ratio of S/N for wide band FM to S/N of DSB-AM (with ma=1) is :

12 views
For identical total transmitted power, the ratio of S/N for wide band FM to S/N of DSB-AM (with ma=1) is : ( Given fm = 15 KHz & frequency. deviation =+/- 75 KHz) a. 112.5 b. 300 c. 75 d. 450

Related questions

One of the necessary and sufficient condition for a network function N(s)=p(s)/q(s) to be a transfer function is that  A) The coefficients of the polynomial p(s) and q(s) must be real and those for q(s) must be positive B) Coefficients of p(s) and q(s) must be real and positive C) Coefficients of p(s) must be positive and real but coefficients of q(s) can be negative also D) Degree of p(s) and q(s) may differ by either zero or one only

For a short transmission line with r/x ratio of is 1.0, the regulation will be zero when the load power factor is

If a signal band limited to fm is sampled at a rate less than 2fm, then the constructed signal will be A) Large in amplitude B) Small in amplitude C) Distorted D) Distortion less

The total power of an AM transmitter having a carrier power of 50 W and the percentage of modulation at 80% is A) 50 W B) 66 W C) 68 W D) 70 W

An Ideal power limited communication channel with additive white Gaussian noise with 1 MHz band width and Signal to Noise ratio of 15 is transmitting the information at theoretical maximum rate. If the Signal to Noise ratio is reduced to 7, how much bandwidth is required to maintain same rate: a. 15/7 MHz b.4/3 MHz c. 2 MHz d. None of these

The total output offset voltage for a noninverting amplifier with input resistance 1 kOhm , feedback resistance 10 k Ohm, input offset voltage 10 mV and input bias current 100 nA is, about  A) 25 mV B) 55 mV C) 110 mV D) 220 mV

Given a unity feedback system with G(s)=k/s (s+4), the value of k for damping ratio of 0.5 is

AM transmitter has a carrier power of 30 W. The percentage of modulation is 85%. Calculate the total power : (A) 5.4 W (B) 40.8 W (C) 10.8 W (D) 20.4 W

The FM radio broad cast frequency band (in MHz) is  A) 68-98 B) 88 -108 C) 148 – 268 D) None of these

If the radiated power of AM transmitter is 10 KW, the power in the carrier for modulation index of 0.6 is nearly:  (1) 8.24 KW (2) 9.26 KW (3) 8.47 KW (4) 9.6 KW

The maximum transmission power efficiency of DSB-C Amplitude modulation is : a. 25% b. 33.33% c. 50% d. 100%

The emf induced in a coil is 1 volt when current in it changes from 0 to 100 mA in time 10mS. Its inductance (in mH) value is  A) 10 B) 50 C) 100 D) 1000

If a current of 500 mA charges a dielectric for 2 s, how much charge is stored in the dielectric?

In order to generate electron-hole pairs, the maximum wavelength of radiation for Silicon (Band gap = 1.1 eV) is  (a) 1.88 μm (b) 1.68 μm (c) 1.13 μm (d) 1.54 μm

A Power system has a total load of 1260 MW at 50 Hz. The load varies 1.5% for every 1% change in frequency. Find the steady state frequency deviation, when a 60 MW load is suddenly dripped if there is no speed control.  (A) 1.667 Hz (B) 50 Hz (C) No change (D) 3.32 Hz

A carrier signal of 600 V rms with 75% amplitude modulation is applied to 75 ohm antenna. The total side band power (in watts) is  A) 4800 B) 450 C) 950 D) 1350

Indicate which one of the following is NOT an advantage of FM over AM? (1) Better noise immunity is provided (2) Lower bandwidth is required (3) The transmitted power is more useful (4) Less modulating power is required

An Ideal power limited communication channel with additive white Gaussian noise is having 4 KHz band width and Signal to Noise ratio of 255. The channel capacity is: a. 8 kilo bits /sec b. 9.63 kilo bits / Sec c. 16 kilo bits / Sec d. 32 kilo bits / Sec

The information rate to be transmitted is 900 bits /sec, FEC is 3/4 , the symbol rate for QPSK modulation scheme is : a. 225 symbols /sec b. 450 symbols /sec c. 600 symbols /sec d. 675 symbols /sec

For a balanced three phase star connected load for which line voltage is 230V and per phase resistance and reactance is 6 Ohm and 8 Ohm respectively. Calculate: 1) phase voltage 2) line current 3) power factor 4) total power absorbed

For a JFET, drain saturation current is 10 mA with Vdd=10 V, Vp= -5V and Vgs= -2 V, drain current in mA is  A) 12.5 B) 8.4 C) 6.2 D) 3.6

For a system with derivative feedback, forward path transfer is G(s) = I / (s2 + s + 1) and feedback path transfer is H(s) = Ks. What is the value of K to obtain a critically-damped closed loop transient response.  (a) 0.5 (b) 0.707 (c) 1 (d) 1.414

An FM signal with modulation index mƒ is passed through a frequency tripler. The modulation index of the output signal will be (1) mƒ (2) 3mƒ (3) 9mƒ (4) 27mƒ

The input to a coherent detector is DSB-SC signal plus noise. The noise at the detector output is:  (1) The in-phase component (2) The quadrature-component (3) Zero (4) The envelope

The following statements are made for FETs 1. In n -channel depletion mode MOS in the active region, the control voltage VGS is negative. 2. NMOS in depletion mode is cut off for VGS=O 3. NMOS in enhance mode is cut off for VGS=O 4. There is no path between source and drain in the enhancement mode Of these, the true statements are : a. 1 and 2 only b. 1 and 3 only c. 3 and 4 only d. 1, 3 and 4 only

The bandwidth and S/N of a communication system are 3MHz and 30dB respectively. The channel capacity (in Mbps) is around  A) 30 B) 300 C) 0.3 D) None of these

Power transmitted through a pipe is maximum when the loss of head due to friction is : (A) one-half of the total head supplied (B) one-third of the total head supplied (C) one-fourth of the total head supplied (D) zero

If 3000 kW power is to be transmitted over a distance of 30 km, the desirable transmission voltage will be.  (A) 11 kV (B) 33 kV (C) 66 kV (D) 132 kV

A 12-bit ADC is operating with a lus clock period and total conversion time is seen to be 14us always. The ADC must be of the type  a. Flash type b. Counting type c. Integrating type d. Successive approximation type

A waveguide termination having VSWR of 1.1 is used to dissipate 100 watts of power. The reflected power will be A) 0.2268 W B) 0.5868 W C) 0.3468 W D) 0.4568 W

If modulation index is 0.6, maximum power efficiency (in %) of AM is about  A) 60 B) 30 C) 20 D) 10

If a current of 1.5 A charges a dielectric for 5 s, how much charge is stored in the dielectric?

Propagation medium of the signal in band (3 to 30) MHz is by  A) Space wave B) Surface wave C) Sky wave D) LOS

Ratio of the rotor reactance X to the rotor resistance R for a two-phase servo motor (A) is equal to that of a normal induction motor (B) is less than that of a normal induction motor (C) is greater than that of a normal induction motor (D) may be less or greater than that of a normal induction motor

The current through a flashlight bulb is 40 mA and the total battery voltage is 4.5 V. The resistance of the bulb is approximately? A.112 ohms B.11.2 ohms C.1.2 ohms D.18 ohms

A 1ms pulse can be stretched to 1 s pulse by using (A) an astable multivibrator (B) a monostable multivibrator (C) a bistable multivibrator (D) a Schmitt trigger circuit

Consider the following statements with regard to power diodes : 1. The breakdown voltage is directly proportional to the doping density of the drift region. 2. Losses in the diode are less due to conductivity modulation of the drift region in the on -state. 3. The vertically oriented structure supports large blocking voltages. Which of the above statements is/are correct ?

A single-phase transformer has a turns ratio of 1 :2 and is connected to a purely resistive load as shown in the figure. The magnetizing current drawn is 1A, and the secondary current is 1A. Ifcore losses and leakage reactances are neglected, the primary current is  A)1.41A B)2A C) 2.24A D)3A

The ratio of the primary to secondary voltage of a transformer is 2:1. The saving in the turns of weight of copper required if an autotransformer is used instead of two winding transformer is (1) 50% (2) 33.33% (3) 66.67% (4) 97%

Response of exp(-2t) of system function 1/(S+1) is  A) exp(-3t) B) exp(-t)+exp(-2t) C) exp(-t)-exp(-2t) D) None of these

The number of independent loops for a network with n nodes and b branches is

Which among the following is the equation for the number of independent loops for a network with n nodes and b branches?  (A) n-1 (B) b+n-1 (C) b-n+1 (D) b-n

The voltage across a coil, when di/dt = 20 mA/s and L = 8 H, is: A. 16 mV B. 160 mV C. 1.6 mV D. 2.5 mV

A system function has a pole at s=0 and a zero at s= -1. The constant multiplier is unity. For an excitation cos(t), What is the steady-state response?  (A) √2sin(t+450) (B) √2sin(t-450) (C) sin(t-450) (D) Sin(t)

Two transformers with identical voltage ratings are working in parallel to supply common load. The percentage impedance of one transformer is higher compared to that of other. The load sharing between the two transformer will: (1) Be proportional to their percentage impedance (2) Be independent of their percentage impedance (3) Be inversely proportional of their respective impedance (4) Depend on the resistance to leakage reactance ratio of each transformer

When cathode is positive with respect to anode in an SCR, the number of blocked p-n junctions is   (a) 1 (b) 2 (c) 3 (d) 4