Practice Test: Electronics Engineering (ECE)- 6 - Electronics and Communication Engineering (ECE)

Select the pair that best express a relationship similar to the one expressed in the question pair:

Ostrich : Bird

A and B together can do a piece of work in 12 days, which B and C together can do in 16 days. After A has
been working it for 5 days and B for 7 days, C finishes it in 13 days. In how many days C alone will do the
work?

Question 6 to 10 carry Two Marks each

Q.

The sufficient condition for matrix ‘A’ to be diagonalizable is

If x = y^a , y = z^b and z = x^c then abc = ?

Out of the four alternatives suggested select the one which is correct

The value of X in the following figure is

The piechart shows the distribution of New York market share by volume of different computer companies
in 2005.

Number of units sold in 2005 in New York = 1,500
Value of units sold in 2005 in New York = US$ 16,50,000

For the year 2005, which company has realised the lowest average unit sales price for a PC ?

If for a 2 × 2 matrix a₁₁ = a₁₂ = a₂₁ = 1 and a₂₂ = –1. If the eigen values of A¹⁹ can be written in the
form then value of a × b is ________________

If X(t ) is random procoss defined as
X(t ) = A + Y (t ) where Y(t ) is zero mean random process and Auto-correlation function of X(t) is defined as

Value of C will be, If A, C are constant

Question 11 to 35 carry One Mark each

Q.

 Value of a is ____________

iⁱ is of the form, where (i= sqrt {-1})

6 boys and 6 girls sit in a row randomly. The probability that all the six girls sit together is in the form 1/a. Value of a is ______________.

The value of current I₁ is

____________________

For a unity feedback system whose open - loop transfer function is   the velocity error is _________________

First derivative of th e signal x(t ) will be

Which unit is adopted for magnit ude measurement in Bode plot s.

Aliasing occurs when sampling frequency ω_s where ω_m is message frequency?

Laplace transform analysis helps in

Which one is not an advant age of SSB over AM

Flash ADC is

In the common base stage of figure. I_CQ = 1mA and β = 7.5 T he input Resistance is

Magnetic field component of a plane wav e in a lossless dielectric is given as

wave is po larized in

A 20 MHz uniform plane wave propagate in lossy dielectric medium which amplit ude is reduced by 20%
aft er every meter traveled. Attenuation constant (Np/m) will be ______________

The figure shows a dependent current source.It

The Laplace transformation of e^at cosh(bt) is

The power factor for the circuit shown is

Consider the transistor circuit shown below

The average power dissipated for one cycle of operation is given by

Common Data Questi on s 29 to 30

Q.

Two amplifiers A and B are to be connectd in cascade. Find out the order in which the amplifiers must be connected to minimise the noise. Amplifiers A has noise factor of 1.5, gain of 10 dB and amplifier B has noise figure 2 dB, gain of 15 dB.

Determine the equivalent noise temperat ure of bot h the amplifiers assuming the reference temperature of
20°C and compare with that of cascaded amlifier.

The JFET in the circuit shown in figure has I_DSS = 10 mA and V_P = –5V and the value of resistance.
R_S for drain current I_DS = 6.4 mA (nearest answer)

Consider the following model of a JFET amplifier

Here I_DSS = 8mA & V_P = –4V the value of V_DS will be

Content of memory location 2070H aft er executing instruction LDAX D is

For the shown circuit below the output volt age V_o is

A Si sample doped with 10¹⁸ /cm³ donar impurit y has a resistance of 10. T he sample has an area of
10^–6 cm²  a length of 10 μm. T he doping efficiency of the sample is

Question 36 to 65 carry Two Marks each

Q.

The value of   where R is the region in the first quadrant bounded by the curve y = x² ,
y + x = 2 and x = 0.

_______________

For  we have y = 1 at x = 0. By using Euler method and taking the step size 0.1. Find the value
of y at x = 0.4.

_________________

If x + y = k is normal to y² = 12x, t hen k is ___________

Determ ine the ran ge of k such that fee dback cont rol system hav ing char acteristic equation
s ( s² + s + 1) (s + 4) + k = 0 will be stable.

The solution of the differential equation, 

Consider the circuit shown in figure

if 4R²C = 3L, t he reson ance frequency ω_o is

What is the transfer funct ion whose approximate plot is shown in figure.

For a unity feedback system with G(s) = 10/s², what would be t he value of centroid

Signal x(t) shown below can be represented as

If memory chip size is 256 × 1 bits, the n umber of chips required for 1 KB memory is

The mininized version of logic circuit shown in figure below is

A man enters into tunnel with velocity v of width 7m and height 4 m and listen th e news through AM
radio signal. Whe n he travels in the tunnel, news spread about bad weather. Select t he correct opt ion
given below

Find the current I for the circuit shown below

Consider an AM system with additive thermal noise having a PSD  η/2 = 10^–12 W/MHz. Assuming that
baseband message signal x(t) has a bandwidth of 4 KHz and the amplitude distribution shown in figure below.

The signal is demodulated by envelope detection and appropriate post detect ion filtering assume M = 1. Find the minimum value of carrier amplitude Ac that will yield (S/No)  40 dB.

Three lossless quart er wave transformer is connected as shown in figure

Which is the necessary condition for no reflection at the input if  

The Y parameter of the two port network shown below is

Consider a transistor circuit the value of 

Consider a periodic signal x(t) shown below

It has Fourier ser ies representation

Choose the true statement.

The electric field strength at distant point, P, due to a point charge, +q, located at the origin, is 100 µ V/m. If the point charge is now enclosed by a perfectly conducting metal sheet sphere whose center is at the origin, then the electric field strength at the point, P, outside the sphere, becomes

For particular. semiconductor material following parameter are observed.

hese parameters are independent of temperature the measure conductivit y of the intrinsic material is 

 The conductivit y at T = 500 K is

Two point charge 1 μC and 4 μC are placed at (–2, 1, 5) and (1, 3, –1) respectively. The energy stored
in the field will be (in mJ)

Value of  

If maximum power transfer will take place in the circuit at   then maximum power transfer to the
load will be

where Z_L = R + jX

Power spectral density of random process x(t) is shown in figure below. It consist of delta funct ion at f = 0
and triangular component . Mean square value of X(t ) is

Find C/R of system shown in figure below

Which of the following is correct signal space diagram (constellation diagram) for the unipolar return to zero code.

For the patterns shown in figure (i) and (ii) if the frequency applied to horizont al plate is 50 Hz t hen,
the frequencies of the vert ical plates will be respectively

A series RL circuit has a constant voltage ‘V’ applied at t = 0. A t what time V_R = V_L