# Technical Interview: Electronics and Communication Engineering

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## Electronics and Communication Engineering

### Signals and Systems

196) What is Fourier statement?

197) Classify signals based on the characteristics.

198) What is mean by non-realizable system?

199) When does a system called invertible.

200) Why do you want to covert signal from time domain into frequency domain?

201) How does Fourier series different from Fourier transform?

202) What is the Discrete Time Fourier Transform?

203) What is the Difference between Laplace Transform and Continuous Time Fourier Transform?

204) What are is the between Z-transform and Discrete Time Fourier Transform?

205) What are the properties of twiddle factor?

206) What is Fast Fourier Transform?

207) How do you analyze a Linear Time Invariant system for its stability?

208) What are the methods available for realization of Linear Time Invariant systems?

209) What is mean by canonical structure?

210) State sampling theorem for Low pass signals.

211) State Sampling theorem for Band pass signals.

212) What is mean by aliasing?

213) How do you avoid aliasing?

214) How do you reconstruct a signal from its sampled version?

215) How do you describe a Linear Time Invariant system?

216) What is the sampling property of an impulse?

217) What are the properties of convolution?

218) What is Region of Convergence (ROC) in Laplace transform?

219) What is ROC in Z-transform?

220) Where does location of poles lie in S-plane for the system to be stable?

221) What do you mean by in place computation for the implementation Fast Fourier Transform algorithm?

222) What is the limitation of Fourier Transform?

223) Define group delay and phase delay.

224) What are the Dirichlet՚s conditions for the existence of Fourier transform?

225) State Parseval՚s theorem.

226) What are the basic signals?

227) What does unit represent in Unit impulse signal?

228) Define energy and power signals.

229) How do you analyze random signals?

230) What do you mean by auto correction and cross correlation?

231) What is the condition required for addition of two periodic signal results into a periodic signal?

232) Classify the signals based o9n their characteristics.

233) How do check the time invariance of a Linear Time Invariant system?

234) How do you test the stability of a Linear Time Invariant system without location of poles?

235) What is the relation between unit step and unit impulse signal?

246) What is mean by Hilbert transform of a signal?

237) List the properties of a Hilbert transform.

238) State initial and final value theorems for Laplace transform.

239) State initial and final theorems for Z transform.

240) When does a system considered as distortion less?

241) What does the Fourier transform of a Gate function?

242) What is the advantage of transposed form of realization of structure?

243) What is the Difference between Decimation in Frequency – Fast Fourier Transform and Decimation in time Fast Fourier Transform?

244) Write the speed improvement factor of Fast Fourier Transform compared to discrete Fourier Transform?

245) How do you find linear convolution using Discrete Fourier Transform?

246) What is the Difference between linear and circular convolution?

247) What is effect in frequency domain of a signal which is shifted in time domain?

248) What is the effect in time domain of a signal which is shifted in frequency domain?

249) What is the relation between number of Fourier coefficients and slope of signal in time domain?

250) How do you find Discrete Fourier Transform of a sequence using linear transformation?

251) Define multirate system.

252) What is mean by interpolation of a sequence?

253) What is mean by decimation of a sequence?

254) How do you change the sampling rate by a non-integer factor?

### Network Theory

255) Ohm՚s law is applicable to …

256) What is the color code for a 220 resister?

257) When parallel resistors are of three different values, which has the greatest power loss?

258) If the current in a circuit equals 0 A, it is likely that … .

259) What is the effect of Resistance on temperature?

260) A Capacitor is driven by a constant current source.

The output across the capacitor will

261) Kirchhoff՚s current law is valid for which circuits?

262) If current flowing through inductance is constant with respect to time the voltage developed across the inductance …

263) Two coupled inductances L1 and L2 having mutual inductances M are connected in series. By a suitable connection, is it possible to achieve a maximum overall inductance?

264) If the voltage across a fixed capacitor is increased, the stored charge will be?

265) The units of measurement of reluctance are?

266) A capacitor has a stored energy of 0.04J with an applied voltage of 200V. The value of capacitance is?

267) Which law is used for finding direction of induced emf?

268) If the voltage across the capacitance is constant with respect to time, the current flowing through it is?

269) The average power delivered by passive element is

270) A series RLC circuit consists of , and ohms is connected across an ac supply of The quality factor of the circuit is?

271) The in a phasor diagram stands for?

272) The half power bandwidth of a series RLC circuit is?

273) In a resonant circuit, the expression for bandwidth in terms of resonant frequency ‘of’ & quality factor ‘Q’ is?

274) Q – factor of a resonant circuit is a measure of

275) A connected planar graph has 4 nodes & 5 branches. The number of meshes in the dual graph will be.

276) If n is the number of nodes then the total number of trees are?

277) In the Thevenin՚s equivalent circuit, equals

278) Reciprocity theorem is application only to

279) In a linear circuit, the superposition principle can be applied to calculate the Norton՚s theorem is a dual of

280) Compensation theorem is applicable to

281) A network having one are more than one source of emf is known as which network?

282) What are bilateral elements?

283) Two heaters, rated at 1000W, 250V each connected in series across a 250V, 50Hz Ac mains the total power drawn from supply would be?

284) The condition for the validity of ohm՚s law is that?

285) The dual of a parallel RC circuit is a ________?

286) A network consists of linear resistors and ideal voltage source. If the value of resistors is doubted, then voltage across each resistor is?

287) Superposition theorem is not applicable for?

288) A current is said to be direct current when it՚s?

289) The form factor of sinusoidal alternating current is?

290) The power factor of an ac circuit lies in between.

291) Unit of reactance power is?

292) If the small capacitance is added to highly inductive circuit then Power factor will be?

293) Real part of admittance is? Imaginary part is?

294) The shunt element of a band pass filter is?

295) The poles and zeros of an all pass network are in which part of s-plane

296) The Euler՚s identity is given by the equation?

297) Unit of inductive reactance is?

298) Substitution theorem is applicable to which networks?

299) Constant k filter is also known as?

300) The units of attention are?

301) In a two-port network, the Z parameter Z11 can be expressed in terms of ABCD parameters as?

302) In a two port networks, the Y parameter Y11 can be expressed in terms of H parameters as?

303) M derived filter is a development of which filter?

304) In the given below circuit, what type of failure will cause the voltage at point B to equal the voltage at point C?