ISRO Scientist/Engineer ECE Solved Papers
Practice previous years' questions for Electromagnetics, Antennas, Microwave Engineering, Digital Communication, Signals & Systems, Analog Electronics, VLSI, and Optical Communications.
All ISRO ECE PYQs / All ECE Subjects / All Topics
Marking scheme: +3.00 positive, -0.75 negative (ICRB Standard).
An inductance of 1 H is realized using air core with 100 turns. What will be the inductance if the number of turns are doubled ?
An inductor of inductance 0.1 H, carrying current of 6 Amps will store energy of
A coil has self resistance of 5Ξ© and inductance of 1 ΞΌH. The value of Q at 1 MHz frequency is
The open loop transfer function of a unity feedback control system is $G(s) = \frac{1}{(s+2)^2}$. The closed loop transfer function will have poles at
The dominant mode of propagation in microstrip line in low frequency approximation is
Consider a transmission line of characteristic impedance 50 ohms and the line is terminated at one end by +j50 ohms, the VSWR produced in the transmission line will be
The divergence of magnetic flux density is
A straight line and a circle of radius a are given. A chord is drawn at random to this circle parallel to the given line. Expected length of the chord is
There is a function f(x), such that $f(0)=1$ and $f'(0)=-1$ and f(x) is positive for all values of x. Then,
Interrupt latency is the time elapsed between:
Inverse Fourier transform of signal $X(j\omega) = 2\pi\delta(\omega) + \pi\delta(\omega - 4\pi) + \pi\delta(\omega + 4\pi)$
Determine the discrete-time Fourier Transform for the signal $x[n] = [-2, -1, 0, 1, 2]$ with the center element at $n=0$
Auto-correlation of a sinusoid $s(t) = A \sin(\omega t)$ is
A source produces 4 symbols with probabilities 1/2, 1/4, 1/8, 1/8. For this source, a practical coding scheme has an average codeword length of 2 bits/symbol. The efficiency of the code is
When signal frequency is 2000 KHz and IF is 455 KHz, the image frequency could be
The Q of RLC tuned circuit with source voltage V in the figure is 100 at resonant frequency of 100 KHz. What is the voltage $V_L$ across inductor at resonance?
A 5V reference is drawn from the circuit shown in the figure. Zener diode of 400mW and 5V with firing current of 5mA is used. The value of $R_S$ is
Find the equivalent resistance R for the network shown in the figure.
The Voltage across last resistor is V. All resistors are unity. Then Vs is given by
Natural frequency of a unity feedback control system of transfer function $G(s) = \frac{10}{s(s+1)}$ is
Which of the following conditions will not guarantee a distortionless transmission line?
For a line of characteristic impedance $Z_0$ terminated in a load $Z_R$ such that $Z_R > Z_0$, the Voltage Standing Wave Ratio (VSWR) is given by
The beamwidth of a reflector antenna of diameter = 70 cm at 30 GHz is
$$T_r = \frac{r}{1 + r^2 + r^4}$$ $$\sum_{r=1}^{\infty} T_r =$$
A man with n keys wants to open a lock. He tries his keys at random. The expected number of attempts for his success is (keys are replaced after every attempt)