ISRO 2018 EC Mini Mock Quiz 3 (Full Syllabus) for ESE & GATE EC Exams

Question 1

To implement 6 × 64 decoder how many number of 2

decoders are required?

Question 2

Three analog signals having band width 1200 Hz, 600 Hz and 600 Hz are sampled at their respective Nyquist Rates, encoded with 12 bit words and time division multiplexed. The bit rate for the multiplexed signal is

Question 3

Two two-port networks

and

are connected such that their input ports are connected in series and their output ports are connected in parallel. Determine the equivalent h-parameters of the series-parallel network, if the T-parameters of the networks

and

are:

Question 4

A 70 kHz bandwidth is to accommodate 7 AM broadcast signals simultaneously. The maximum modulation frequency must each station be limited to _____ kHz. Assume that a guard band of 5 kHz is also present.

Question 5

In 555-timer circuit, if output is low then current will flow through device and switch it on. It is a case of:

Question 6

Find the maximum undistortion sine wave amplitude if the IC 741 OPAMP has a slew rate of 0.8 V per microsecond. IF this is used at a frequency of 4.86 KHZ?

Question 7

Consider the periodic square wave in the figure shown.

The ratio of the power in the 7^th harmonic to the power in the 5^th harmonic for this waveform is closest in value to _______.

Question 8

A point charge of 21 nC has a velocity of

. Determine the magnitude of the force exerted [in µN] on the charge by the electric field of which the flux density is

kV/m.

Question 9

The feedback amplifier shown in fig. makes use of an op amp with internal gain (open loop gain) A = 10⁵. How much is the output voltage for input signal vs = 2mV in the circuit shown.

Question 10

Keeping the value of load reactance fixed, the load resistance is varied to draw maximum power from the circuit. If the load resistance is fixed at 10Ω, determine the value of R in the given circuit.

Question 11

Find the region of convergence for the following function f(t)

Question 12

The doping concentrations on the p-side and n-side of a silicon diode are A forward bias of 0.3 V is applied to the diode. At T = 300K, the intrinsic carrier concentration of silicon The electron concentration at the edge of the depletion region on the p-side is

Question 13

Find the value of RB to design a second order butter worth voltage control voltage source band worth filter with

and gain at central frequency is 10 and given R =1k and Ra=1k?

Question 14

Consider an ideal silicon P-N junction diode with the following parameters

The ratio of

so that 95% of current in depletion region is carried by electron is

Question 15

Consider a region of silicon device of electrons and holes, with an ionized donor density of

. The electric field at x = 0 is 0 V/cm and the electric field at x = L is 50 kV/cm in the positive x direction. Assume that the electric field is zero in the y and z directions at all points.

Given q =1.6 x10^-19 coulomb,

for silicon, the value of L in nm is_____

Question 16

What will be the current in the circular coil of radius 15 cm having magnetic field strength of 2,000 A/m, if the coil is wound with 250 turns.

Question 17

Consider an air-filled rectangular waveguide with dimensions a = 2.286 cm and b = 1.016 cm. At 10 GHz operating frequency, the value of the propagation constant (per meter) of the corresponding propagating mode is _________.

Question 18

What are the advantage of clocking of a flip flop
1. Suppression of noise
2. Ascertaining the operation at a specified point of time
3. Synchronization with other operation

Select the correct answer using the code given

Question 19

For the given circuit, determine the value of R, if the current through the diode is 5.5 mA. Given, E = 12 V, and the diode is a germanium diode.

Question 20

There are two roads from A to B and two roads from B to C. Each of the four roads is blocked by snow with probability p, independently of the others. Find the probability that there is an open road from A to B given that there is no open route from A to C