BSc Third Year (Sem 5 & 6) Physics – Daily Revision MCQ (English Medium)
This is the set for 26 October 2026. Solve today's MCQs →
Timed quiz: 15 seconds per question, the next one loads by itself when time runs out. Or solve without the timer: tap an option, right turns green, wrong turns red. New sets are added regularly.
Or scroll down and solve without the timer.
According to Gauss's law, what is the total electric flux through a closed surface that encloses a net charge q in vacuum?
Chapter 1: Electrostatics and Gauss's Law
Show answer
Answer: B. q/ε₀
Gauss's law: total flux through any closed surface = (net charge enclosed)/ε₀ = q/ε₀; it is zero only when no net charge is inside.A DC source has an internal (Thevenin) resistance of 4 Ω. For maximum power to be transferred to the load, the load resistance should be:
Chapter 3: DC Circuits and Network Theorems
Show answer
Answer: D. 4 Ω
Maximum power transfer theorem: power in the load is maximum when R_L equals the source (Thevenin) resistance, here 4 Ω.At resonance in a series LCR circuit, the impedance of the circuit is:
Chapter 4: Alternating Current Circuits
Show answer
Answer: A. Minimum and equal to R
At resonance X_L = X_C, so Z = √(R² + (X_L − X_C)²) = R, which is the minimum possible impedance.What is the maximum theoretical efficiency of a full-wave rectifier?
Chapter 9: Semiconductor Diodes and Rectifiers
Show answer
Answer: C. 81.2%
η_max = 8/π² ≈ 0.812 for a full-wave rectifier, double the 40.6% of a half-wave rectifier.Which diode is used as a voltage-controlled variable capacitor?
Chapter 10: Optoelectronic and Special Diodes: LED, Photodiode, Solar Cell, Varactor
Show answer
Answer: B. Varactor diode
A reverse-biased varactor's depletion-layer width, and hence its capacitance, changes with the applied reverse voltage.A transistor has a common-base current gain α = 0.98. What is its common-emitter current gain β?
Chapter 11: Transistors
Show answer
Answer: A. 49
β = α/(1 − α) = 0.98/0.02 = 49.An op-amp inverting amplifier has Rf = 100 kΩ and Rin = 10 kΩ. What is its voltage gain?
Chapter 12: Operational Amplifiers
Show answer
Answer: D. −10
Inverting amplifier gain A = −Rf/Rin = −100/10 = −10 (the minus sign shows a 180° phase shift).The de Broglie wavelength of a particle having momentum p is:
Chapter 13: Origin of Quantum Mechanics
Show answer
Answer: C. h/p
de Broglie proposed that every moving particle has a wave associated with it, of wavelength λ = h/p.For a particle in a one-dimensional infinite potential box, what is the ratio E₂/E₁ of the second energy level to the first?
Chapter 14: Schrödinger Equation
Show answer
Answer: A. 4
E_n = n²h²/(8mL²), so energy ∝ n²; E₂/E₁ = 2²/1² = 4.In a Raman spectrum, compared with the incident (Rayleigh) line, the Stokes lines appear at:
Chapter 20: Raman Effect
Show answer
Answer: D. Lower frequency (longer wavelength)
In Stokes scattering the molecule takes energy from the photon, so the scattered light has lower frequency; anti-Stokes lines lie at higher frequency.
BSc Third Year (Sem 5 & 6): MCQ in other subjects
All questions are written by PadhaiNotes in our own words from the common syllabus of Maharashtra universities (NEP). Your own university's syllabus may differ a little.