As you as king for the previous year question paper of ECIL recruitment the question paper is as follow:



1. When a inductive coil connected to a 200 V, 50Hz ac supply with 10A current flowing through it dissipates 1000 watts then which of the following will have least value in ohms-
a.) Resistance
b.) Reactance
c.) Impedance
d.) None

2.Oscillator crystal are made of ?
a.) Silicon
b.) Germanium
c.) Quartz
d.) None

3. For small size, high frequency coils, the most common core material is-
a. )Air
b. )Ferrite
c.) Powdered ion
d.) Steel

4.If we have a parallel plate capacitor of plate area ?A? and plate separatoin t and having a capacity C and a metallic plate r of area A and of negligible thickness is introduced in thecapacitor at a distance from either of the two plates as shown in the given figure then the capacity of the capacitor will become ?
a.)
b.) C
c.) 2C
d.) 4C

5.A superconductor is a ?
a.) A material showing perfect conductivity and Meissner effect below a critical temperature
b.) A conductor having zero resistance
c.) A perfect conductor with highest di-magnetic susceptibility
d.) A perfect conductor which becomes resistance when the current density through it exceeds a critical value

6.When an inductor tunes at 200 KHz with 624 pF capacitor and at 600 KHz with 60.4 pF capacitor then the self capacitance of the inductor would be ?
a) 8.05 pF
b) 10.05pF
c.) 16.01pF
d.) 20.01pF

7.Sparking occur when a load is switched off because the circuit has high ?
a.) Inductance
b.) Capacitance
c.) Resistance
d.) None

8.Sparking between contacts can be reduced by inserting a ?
a.) Resistance in the line
b.) Capacitor in series with contacts
c.) Capacitor in parallel with contacts
d.) None

9.RF amplifier of an A.M. receiver is normally biased in ?
a.) Class ?A?
b.) Class ?b?
c.) Class ?C?
d.) None

10.The value of gate voltage for the operation of enhancement of only N channel MOSFET has to be ?
a.) High positive
b.) High negative
c.) Low positive
d.) Zero

11.The input gate current of a FET is ?
a.) a few microamperes
b.) negligibly small
c.) a few milliamperes
d.) a few amperes

12.In the following fig. with R = 30k, the value of current through 2 K resistor is ?
a.) 25 mA
b.) 40 mA
c.) 25/16 mA
d.) 10 mA

13.A step recovery diode ?
a.) has on extremely short recovery time
b.) conducts equally well in both directions
c.) is mainly used as a harmonic generator
d.) is an ideal rectifiers of high frequency signals

14.In order to get maximum undistorted output signal from CE amplifier with VCC 10V, the value of VCE (Q) should be approximately-
a.) 0.1V
b.) 5V
c.) 10V
d) V

15.In a FET the electrode, which corresponds to collector in bipolar transistor, is ?
a.) source
b.) drain
c.) gate
d.) none

16.The device which acts like an NPN and a PNP transistor connected base to base and emitter to collector is ?
a.) Triac
b.) UJT
c.) Diac
d.) SCR

17.A typical optical fibre has ?
a.) High refractive index core and low refractive index cladding
b.) Low refractive index core and high refractive index cladding
c.) Both a and b
d.) None

18.In the following figure circuit diagram of an op-amp based is shown. The ratio is equal to ?
a.) 9
b.) 11
c.) 10
d.) 21

19.When a loud speaker is connected across the terminals A and B of the network shown in the fig. then its impedance to obtain maximum power dissipation in it will be ?
a.) 3 ? j1
b.) 3 + j9
c.) 7.5 + j 2.5
d.) 7.5 ? j 2.5

20.In the lattice network, the value of R for the maximum power transfer to the load ?
a.) 5
b.) 6.5
c.) 8
d.) 9

21.For a lossy transmission line short circuited at the receiving end, the input impedance is given by (Z0 is the characteristic impedance, ֠is the propagation constant and l is the length of the line-
a.) Z0 cot h ?b.) Z0 cot ?c.) Z0 tan h.֠ld.) Z0 tan ?

22.The approximate thickness of the radome wall should be ?
a.) l
b.) l/4
c.) l/2
d.) l/8

23.A relatively permanent information is stored in
a. ) ROM
b.) RAM
c.) PROM
d.) Volatile memory

24.The rise time of the RC network shown in the given figure is approximately equal to ?
b.) RC
c.) 2RC
d.) 4RC

25.If in the network shown in the fig. initially a steady state is attained by closing the switch ?s? and then if the switch is opened at t = 0, then thecurrent i(t) through the inductor will be ?
a.) cos50tA
b.) 2A
c.) 2cos100tA
d.) 2sin50tA

26.When the p network of figure ? I and T-network of figure ? II are equivalent then the values of R1, R2 and R3 will be respectively ?
a) 9W, 6W and 6W
b.) 6W, 6W and 9W
c.) 9W, 6W and 9W
d.) 6W, 9W and 6W

27.When the impedance matrices of a two port networks are given by and , then if these two networks are connected in series then the impedance matrix of the resulting two-port network will be ?

28.Joule/coulomb is the unit of -
a.) Electric field potential
b.) Potential
c .) Charge
d.) None of the above

29.The electric field line and equipotential lines-
a.) Are parallel to each other
b.)Are one and same
c.) Cut each other orthogonally
d.)Can be inclined to each other at any angle

30.For a lossy transmission line short circuited at the receiving end, the input impedance is given by (When Z0 is the characteristic impendence g is the propagation constant and L is the length of the line

31.When two equal positive point charges are placed along X- axis at X1 and ?X1 respectively then the electric field vector at a point P on the positive Y-axis will be directed-
a.) In the +x direction
b.) In the ?x direction
c. ) In the +y direction
d.) In the ?y direction