Free Practice Questions for ISRO Scientist/Engineer SC (Electronics)

Exam-style questions and explanations by OpenExamPrep.

✓ No registration✓ No credit card

100+ Questions

100% Free

Loading practice questions...

Same family resources

Explore More India PSU Engineering Recruitment Exams

Continue into nearby exams from the same family. Each card keeps practice questions, study guides, flashcards, videos, and articles in one place.

More From This Family

Videos and articles for deeper review.

ArticleCIL MT Exam Pattern 2026: Two-Paper Strategy, Qualifying Floors, and What Happens Next15 min read

Sample ISRO Scientist/Engineer SC (Electronics) Practice Questions

Try these sample questions to review concepts for the ISRO Scientist/Engineer SC (Electronics) exam. Each question includes a detailed explanation. Start the interactive quiz above for the full 100+ question experience with AI tutoring.

1In a series RLC circuit at resonance, the impedance is:

A.Minimum and purely resistive

B.Maximum and purely inductive

C.Zero

D.Purely capacitive

Explanation: At resonance, inductive reactance XL equals capacitive reactance XC, so they cancel. The circuit reduces to R only, giving minimum impedance equal to the resistance.

2Thevenin equivalent voltage Vth across terminals of a linear network is:

A.Short-circuit current times Rth

B.Open-circuit voltage at the terminals

C.Voltage across the load resistor

D.Sum of all internal source voltages

Explanation: Thevenin voltage is defined as the open-circuit voltage between the two terminals after the load is removed. Rth is found from the equivalent resistance with independent sources deactivated.

3For a reciprocal two-port network, which condition holds for the ABCD (transmission) parameters?

A.ZY = 1 for all ports

B.AB − CD = 1

C.AD − BC = 1

D.h11 h22 − h12 h21 = 0 always

Explanation: For a reciprocal two-port, the transmission (ABCD) matrix satisfies AD − BC = 1. This reciprocity condition links cascade parameters of passive reciprocal networks.

4A coil of resistance 10 Ω and inductance 0.1 H is connected to 230 V, 50 Hz supply. The power factor of the circuit is approximately:

A.1.00

B.0.95

C.0.60

D.0.30

Explanation: XL = 2πfL = 2π × 50 × 0.1 ≈ 31.4 Ω. |Z| = √(10² + 31.4²) ≈ 33 Ω. Power factor = R/|Z| = 10/33 ≈ 0.30.

5In a balanced three-phase star-connected load, the line voltage is 400 V. The phase voltage is:

A.230 V

B.400 V

C.346 V

D.693 V

Explanation: For a star connection, Vphase = Vline / √3 = 400 / 1.732 ≈ 230 V. Line current equals phase current in star.

6The quality factor Q of a series RLC circuit at resonance is given by:

A.R / (ω₀ L)

B.ω₀ L / R

C.ω₀ C / R

D.R / (ω₀ C)

Explanation: For a series RLC circuit, Q = ω₀L/R = 1/(ω₀CR) = (1/R)√(L/C). It measures resonance sharpness (energy stored vs energy dissipated per cycle).

7Maximum power transfer to a purely resistive load RL from a linear DC Thevenin source (Vth, Rth) occurs when:

A.RL = Rth/2

B.RL = 2 Rth

C.RL = Rth

D.RL = 0

Explanation: For a resistive DC network, maximum load power occurs at RL = Rth (efficiency 50% at that point). AC networks with reactance require conjugate matching.

8A capacitor of 10 μF is charged to 100 V. The energy stored is:

A.1 J

B.100 mJ

C.500 mJ

D.50 mJ

Explanation: Energy W = ½CV² = 0.5 × 10×10⁻⁶ × 100² = 0.5 × 10⁻⁵ × 10⁴ = 0.05 J = 50 mJ.

9In a π-filter used for power supply smoothing, the component placed across the load is typically:

A.Shunt capacitor

B.Series inductor only

C.Series resistor

D.Shunt inductor only

Explanation: A π-filter has shunt capacitors at input and output with a series inductor between them. The output shunt capacitor bypasses ripple to ground, smoothing the DC.

10For a network function H(s) = 1/(s² + 2ζωₙs + ωₙ²), critical damping occurs when ζ equals:

A.0

B.1

C.0.5

D.2

Explanation: The standard second-order system has poles at −ζωₙ ± ωₙ√(ζ²−1). Critical damping corresponds to ζ = 1 (repeated real poles). ζ < 1 is underdamped; ζ > 1 is overdamped.

About the ISRO Scientist/Engineer SC (Electronics) Exam

The ISRO Scientist/Engineer 'SC' Electronics written test recruits B.E./B.Tech. graduates into India's space programme. The exam tests core ECE knowledge at undergraduate depth plus aptitude, followed by a technical interview. Successful candidates join ISRO centres as Scientist/Engineer 'SC' working on satellites, launch vehicles, and ground systems.

Exam sponsor: ISRO Centralised Recruitment Board (ICRB). The requirements and fees below concern the certification or admission exam, separate from our free practice resources.

Assessment

Two-stage selection per ICRB Scientist/Engineer 'SC' recruitment: (1) Written test — 95 objective MCQs totalling 100 marks in 120 minutes with Part A core electronics (80 questions, +1 correct, −1/3 wrong) and Part B aptitude (15 questions, 20 marks, no negative marking); (2) Personal interview for candidates shortlisted in approximately 1:5 ratio. Appointed as Scientist/Engineer 'SC' on Level 10 (7th CPC pay matrix).

Time Limit

120 minutes

Passing Score

No fixed qualifying mark published; written-test cutoffs are announced discipline-wise after the exam for interview shortlisting

Exam / Certification Fees

₹750 processing fee per application (includes ₹250 non-refundable application fee); partial or full refund on appearing per category rules in the active notification

Exam sponsor website

Fees, eligibility, and exam policies can change. Confirm them with the exam sponsor before applying or paying.

Official sources

Our practice resources: topics covered

We aim to reflect publicly available exam outlines and topic information in our study resources. Coverage, format, and difficulty may differ from the actual exam, and we cannot guarantee that every detail is accurate or current. Confirm exam requirements, fees, and policies with the official exam sponsor.

10%

Network Theory

AC circuits, resonance, Thevenin/Norton, two-port parameters, three-phase systems, filters

10%

Electronic Devices

Semiconductor physics, PN junction, BJT, MOSFET, optoelectronics, fabrication basics

10%

Analog Electronics

Op-amps, amplifiers, oscillators, active filters, ADC/DAC, precision rectifiers

10%

Digital Electronics

Boolean algebra, combinational/sequential circuits, counters, memory, logic families, 8085 basics

10%

Control Systems

Transfer functions, stability, Routh-Hurwitz, Bode/Nyquist, root locus, PID, state-space

10%

Communication Systems

Sampling, AM/FM, PCM, digital modulation, Shannon capacity, coding, receivers

Electromagnetics

Maxwell's equations, plane waves, transmission lines, waveguides, antennas, link budget

12%

Signals, Systems & Engineering Math

Laplace/Fourier/Z-transforms, LTI systems, convolution, probability, linear algebra, ODEs

20%

General Aptitude

Quantitative aptitude, logical reasoning, verbal ability, general awareness including ISRO/space context

Preparing for the ISRO Scientist/Engineer SC (Electronics) Exam

What You Need to Know

Passing score: No fixed qualifying mark published; written-test cutoffs are announced discipline-wise after the exam for interview shortlisting
Assessment: Two-stage selection per ICRB Scientist/Engineer 'SC' recruitment: (1) Written test — 95 objective MCQs totalling 100 marks in 120 minutes with Part A core electronics (80 questions, +1 correct, −1/3 wrong) and Part B aptitude (15 questions, 20 marks, no negative marking); (2) Personal interview for candidates shortlisted in approximately 1:5 ratio. Appointed as Scientist/Engineer 'SC' on Level 10 (7th CPC pay matrix).
Time limit: 120 minutes
Exam / certification fees: ₹750 processing fee per application (includes ₹250 non-refundable application fee); partial or full refund on appearing per category rules in the active notification Official sources

Using Our Practice Resources

Work through all 100 available questions
Review every answer and explanation
Track weak areas and revisit them
Use our AI tutor for tough concepts

ISRO Scientist/Engineer SC (Electronics): Suggested Study Strategy

1Revise GATE EC-level topics — ISRO electronics papers heavily overlap with networks, devices, analog/digital, communications, control, and electromagnetics.

2Practice timed mocks at ~95–100 questions in 120 minutes; manage negative marking in Part A (−1/3) by skipping uncertain items.

3Part B aptitude has no negative marking — attempt all aptitude items after finishing Part A practice.

4Solve official previous-year ICRB electronics papers posted on isro.gov.in under the active recruitment advertisement.

Frequently Asked Questions

What is the ISRO Scientist/Engineer SC Electronics exam pattern?

Per ICRB Scientist/Engineer 'SC' pattern (confirm in the live advertisement), the written test has 95 MCQs totalling 100 marks in 120 minutes. Part A has 80 discipline-specific questions with +1 mark for correct and −1/3 for wrong answers. Part B has 15 aptitude MCQs worth 20 marks total with no negative marking.

What is the ISRO ICRB application fee?

All candidates pay ₹750 per application (including a ₹250 non-refundable application fee). Women, SC/ST, and PwBD candidates receive a full ₹750 refund on appearing; male General/OBC candidates receive ₹500 back on appearing, per the official FAQ.

Is there a published passing score for the ISRO written test?

ISRO does not publish a fixed qualifying percentage in advance. Discipline-wise cutoffs are set after the exam based on performance and vacancy, and candidates are shortlisted for interview in approximately a 1:5 ratio.

How does this practice bank match the real exam?

This bank provides 80 ECE core questions and 20 aptitude items to mirror the official 80:20 technical-to-aptitude split. Topics align with undergraduate ECE syllabus and previous ICRB electronics papers; drill official previous-year papers on isro.gov.in for exact style.

Free Practice Questions for ISRO Scientist/Engineer SC (Electronics)

Explore More India PSU Engineering Recruitment Exams

Coal India Management Trainee (CIL MT)

BEL Probationary Engineer exam

ISRO Scientist/Engineer — Civil

ISRO Scientist/Engineer — Computer Science

ISRO Scientist/Engineer — Electrical

ISRO Scientist/Engineer — Mechanical