Every exam has a unique syllabus, pattern and difficulty.Similarly ISRO exam has its own features.Here I attempt to give the various topics that are repeated in the ISRO SCIENTIST exam ECE.

**Some of the topics usually covered are**

1.Diode Circuits-Zener Voltage Regulator,Series Parallel diode Circuits,Rectifiers,Clippers&Clampers

2.Converters-ADC,DAC

3.Filters-Circuit identification,features of various filters

4.Simple logic circuit simplification

5.Universal gate problems-use of NAND and NOR to implement other gates

6.Series parallel networks problems

7.RLC Circuits-Resonant frequency,bandwidth,Q factor calculation,Time Consatant (most repeated topic)

8.Amplitude Modulation-Total Power,Modulation Index,Power Saving Calculation,

9.Frequency Modualtion-Deviation,Modulation Index,Sideband,Adavntages and disadvantages,Circuits for detection and modualtion,Envelope detector based time constant calculation,Pre&De emphasis circuitry

10.Phase Modulation-Deviation,Comparison with FM, generation using Integrator and Differentiator

11.VSWR Calculation-Using reflection coefficient,Directional Coupler,load imp& char impedance given

12.Characteristic Impedance- OC and SC impedance of line given,lossless line

13.Code converter circuits-Gray to Binary,Excess 3 ,etc.

14.Shannon's Channel Capacity Theorem

15.Standard of Laplace Transforms

16.Basic Z Transforms

17.OpAmps-Calculation of CMRR,Slew Rate,Application-Summer

18.Relations of maxwell equations,calculation of intrinsic impedance

19.Covolution with unit impulse function

20.Memory Chip design-Given

21.QPSK features

22.Radar-Duty Cycle,Maximum Range calculation

23.Counters-Modulus calculation,RING COUNTER,JOHNSON COUNTER-Calculation of counts

24.Characteristic equation of Flip Flops

25.Calcualtion of Noise figure in casacade blocks

26.Superhetrodyne Reciever- Calculation of Image frequency,Image rejection ratio

27.Microprocessor-loop based programs,some features of various registers

The Above mentioned topics are important and repeated often but they themselves are not enough. Studying these will give you a scope of learning other topics.

**Refernce books**

1.Electronic Devices and Circuits-Sallivahnan

2.Electronic Communication Systems-Wayne Tomsai

3.Mathematics-Erwin Kreyszig

4.Digital Electronics-MorrisMano

5.Digital Signal processing- Sallivahnan

6.Communication System-Simon Haykin

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