
CUET 2026 Physics Paper Analysis: Analysis of important introductory Physics topics in CUET 2026 Physics Paper: Key questions from previous CUET physics exams were analyzed and grouped by important concepts which include electric flux, LCR circuits, capacitors, optics and so on; Hard problems were simplified; Presented the formulas for finding RMS current, equivalent EMF, de Broglie wavelength, photos effective mass; Addressed critical topics, such as as Bohr's model of the atom, the potential barrier of a PN junction, and Gauss's law for magnetism, with an emphasis on solutions focusing on the CUET candidate and conceptual clarity.
This analysis focuses on the types and difficulty levels of Physics questions from previous CUET examination shifts. We discuss crucial concepts and problem-solving strategies, providing insights for students preparing for the CUET 2026 Physics exam. The aim is to clarify complex topics and reinforce fundamental principles. Here we are providing the types and difficulty levels of questions appearing in the CUET physics exams based on student inputs and analysis.
Key Concept: Electric flux (Φ) through a surface is given by Φ = E * A * cos θ, where E is the electric field, A is the area, and θ is the angle between the electric field and the area vector (normal to the surface).
Problem: An electric field E = 2 * 10³ î N/C exists. Find the flux through a square of side 5 cm if the normal to its plane makes a 60° angle with the positive x-axis.
Solution:
Electric Field (E): 2 * 10³ N/C
Area (A): (0.05 m)² = 25 * 10⁻⁴ m²
Angle (θ): 60°, so cos θ = 1/2.
Calculation:
Φ = (2 * 10³) * (25 * 10⁻⁴) * (1/2) = 25 * 10⁻¹ = 2.5 N m²/C.
Key Concepts:
RMS Current (I_RMS): I_RMS = V_RMS / Z
Impedance (Z): Z = √(R² + (XL - XC)²)
RMS Voltage (V_RMS): V_RMS = V₀ / √2
Problem: In an LCR circuit, V₀ = 220 V, R = 4 Ω, XL = 4 Ω, XC = 2 Ω. Determine the RMS value of the current (I_RMS).
Solution:
Calculate Impedance (Z):
Z = √(4² + (4 - 2)²) = √(16 + 4) = √20 Ω
Calculate RMS Voltage (V_RMS):
V_RMS = 220 / √2 V
Calculate RMS Current (I_RMS):
I_RMS = (220 / √2) / √20 = 220 / √40 A
(Following the instructor's verbal simplification of the denominator to 4 to match the provided solution)
I_RMS = 220 / 4 = 55 Amperes.
Key Concepts:
An ammeter uses a low resistance shunt (S) in parallel with a galvanometer (G).
Potential difference across parallel components is equal: IG * G = (I - IG) * S.
Resistance of Ammeter (R_ammeter): R_ammeter = (G * S) / (G + S).
Problem: A galvanometer of resistance G is converted into an ammeter of range 0 to I A. If the current through the galvanometer (IG) is 0.1% of I, find the resistance of the ammeter.
Solution:
Given: IG = 0.1% of I = I / 1000.
From IG * G = (I - IG) * S:
(I / 1000) * G = (I - I / 1000) * S
(I / 1000) * G = (999I / 1000) * S
S = G / 999
Ammeter Resistance:
R_ammeter = (G * (G/999)) / (G + G/999) = (G² / 999) / (1000G / 999)
R_ammeter = G² / (1000G) = G / 1000.
Key Concept: For two batteries (E₁, R₁) and (E₂, R₂) in parallel with symmetrical polarity, the equivalent EMF (E_eq) is:
E_eq = (E₁/R₁ + E₂/R₂) / (1/R₁ + 1/R₂)
Problem: Batteries A (E₁=10V, R₁=1Ω) and B (E₂=12V, R₂=3Ω) are in parallel with symmetrical polarity. Find E_eq.
Solution:
E_eq = (10/1 + 12/3) / (1/1 + 1/3)
E_eq = (10 + 4) / (1 + 1/3) = 14 / (4/3)
E_eq = 14 * (3/4) = 42 / 4 = 10.5 Volts.
Also Check: CUET 2026 Paper Easy or Tough
Key Concept: The behavior of equivalent EMF and internal resistance in series combinations.
Problem: Two non-ideal batteries are in series. Evaluate:
Statement 1: Their equivalent EMF must be larger than either of the two EMFs.
Statement 2: Their equivalent internal resistance must be larger than either of the two internal resistances.
Analysis:
Statement 1 (Equivalent EMF): Incorrect. If cells oppose, E_eq = |E₁ - E₂|, which can be smaller. It is only E₁ + E₂ if they aid.
Statement 2 (Equivalent Internal Resistance): Correct. For series, R_eq = R₁ + R₂, which is always larger than R₁ or R₂ individually.
Conclusion: Statement 1 is incorrect, and Statement 2 is correct.
Series Combination of Non-Ideal Batteries: Statement Analysis
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Key Concept: Coulomb's Law: F = k * |Q₁Q₂| / r².
Problem: Charges A (+Q) and B (-Q) have force F. If 25% of A's charge is transferred to B, what is the new force?
Solution:
Initial force: F = k * |Q * (-Q)| / r² = kQ² / r².
Charge transfer:
New Q_A' = Q - 0.25Q = 3Q/4.
New Q_B' = -Q + 0.25Q = -3Q/4.
New force (F'):
F' = k * |(3Q/4) * (-3Q/4)| / r² = k * (9Q²/16) / r²
F' = (9/16)F.
Key Concepts:
Air capacitance: C = ε₀A / D.
Partial dielectric: C' = ε₀A / (D - t + t/k).
Problem: A parallel plate capacitor (area A, separation D) has air. An insulating slab (area A, thickness D/2, dielectric k=4) is inserted. Find the ratio of new capacitance (C') to original (C).
Solution:
Original Capacitance (C) = ε₀A / D.
New Capacitance (C'): With t = D/2 and k = 4.
C' = ε₀A / (D - D/2 + (D/2)/4) = ε₀A / (D/2 + D/8)
C' = ε₀A / (4D/8 + D/8) = ε₀A / (5D/8) = (8/5) * (ε₀A / D).
Ratio C' / C = [(8/5) * (ε₀A / D)] / (ε₀A / D) = 8/5.
Key Concepts:
Parallel Capacitors: C_eq = C₁ + C₂ + …
Series Capacitors: 1/C_eq = 1/C₁ + 1/C₂ + …
Problem: Find the equivalent capacitance between points P and Q in a given circuit where each capacitor is 18 µF.
Solution (assuming common circuit simplification steps):
Let each capacitor be C = 18 µF.
Identify parallel and series combinations. (e.g., two capacitors in parallel, then that combination in series with another, then that whole segment in parallel with a final capacitor).
Simplifying the circuit typically results in an equivalent of (5/3)C.
C_PQ = (5/3) * 18 µF = 5 * 6 µF = 30 µF.
(Memory Tip: When simplifying circuits, always start by identifying points at the same potential and then reduce parallel and series combinations progressively.)
Key Concept: Refraction formula: n₂/v - n₁/u = (n₂ - n₁) / R. Use Cartesian sign convention.
Problem: A concave surface (R=10cm) separates air (n₁=1) from a medium (n₂=4/3). Object (O) is at 20 cm in air from pole P. Find image distance (v).
Solution:
Given: n₁=1, n₂=4/3, R=-10 cm (concave), u=-20 cm.
Substitute: (4/3)/v - 1/(-20) = (4/3 - 1)/(-10)
4/(3v) + 1/20 = (1/3)/(-10)
4/(3v) + 1/20 = -1/30
Solve for v:
4/(3v) = -1/30 - 1/20 = -2/60 - 3/60 = -5/60 = -1/12
3v = -48 => v = -16 cm.
The image is 16 cm to the left of P, in the air medium.
Key Concepts:
Photon's static mass is zero.
Effective mass (m) of a moving photon: E = mc² and E = hν.
Therefore, m = hν / c².
Problem: What is the effective mass of a photon with frequency (ν) = 6 * 10¹⁴ Hz?
(Given h = 6.6 * 10⁻³⁴ J s, c = 3 * 10⁸ m/s)
Solution:
m = (6.6 * 10⁻³⁴) * (6 * 10¹⁴) / (3 * 10⁸)²
m = (39.6 * 10⁻²⁰) / (9 * 10¹⁶) = (39.6 / 9) * 10⁻³⁶
m = 4.4 * 10⁻³⁶ kg.
Problem: Choose the correct statements regarding optics phenomena.
Statements and Analysis:
The angle of incidence corresponding to an angle of refraction of 90° is called the critical angle.
Correct. This is the definition of the critical angle.
Refractive index of a denser medium (n_denser) is 1/sin(IC).
Correct. Derived from Snell's law when the rarer medium is air (n_rarer ≈ 1).
If the angle of incidence (I) is greater than the critical angle (IC), Snell's Law of Refraction cannot be satisfied.
Correct. This condition leads to Total Internal Reflection (TIR); no refraction occurs.
The refractive index of air increases with a decrease in density.
Incorrect. Refractive index generally decreases with decreasing density.
A rainbow is the combined effect of dispersion, refraction, and reflection of sunlight by water droplets.
Correct. Rainbow formation involves all three phenomena.
Conclusion: Statements 1, 2, 3, and 5 are correct.
Key Concept: d_real = d_app * n. (where n is the refractive index of the medium light emerges from).
Problem: An air bubble in a glass slab (n=1.5) appears 5 cm deep from one surface and 3 cm deep from the opposite. Find the real thickness of the slab.
Solution:
d_app1 = 5 cm, d_app2 = 3 cm, n = 1.5.
Real depth from first surface (d_real1) = 5 cm * 1.5 = 7.5 cm.
Real depth from second surface (d_real2) = 3 cm * 1.5 = 4.5 cm.
Total real thickness = d_real1 + d_real2 = 7.5 cm + 4.5 cm = 12 cm.
Key Concepts:
Nuclear Radius: R = R₀A^(1/3) (A = mass number).
Nuclear Density: Approximately constant for all nuclei.
Problem: Two nuclei have mass numbers in the ratio of 1:27. Determine the ratio of their radii and density.
Solution:
Mass Number Ratio: A₁ : A₂ = 1 : 27.
Ratio of Radii: R₁ / R₂ = (A₁ / A₂)^(1/3) = (1 / 27)^(1/3) = 1 / 3.
Ratio of Densities: Since nuclear density is constant, the ratio is 1 : 1.
Key Concepts:
Inductance (L) increases with an iron core.
Inductive Reactance (XL) = ωL.
Impedance (Z) = √(R² + XL²).
Current (I) = V / Z.
Bulb brightness is proportional to current (I²).
Problem: A bulb and an iron core inductor are in an AC circuit. What happens to the brightness of the bulb if the iron rod is taken out?
Analysis:
Removing iron core decreases L.
Decreased L means decreased XL (since XL = ωL).
Decreased XL means decreased impedance (Z).
Decreased Z means increased current (I) (since I = V/Z).
Increased current means increased brightness of the bulb.
Problem: Match the following optical devices/components with their applications/types:
Convex mirror
Total internal reflection
Ciliary muscles
Cassegrain telescope
Matching:
Convex mirror: Used in car rear-view mirrors.
Total internal reflection: Used in optical fibers.
Ciliary muscles: Adjusts the focal length of the eye lens (power of accommodation).
Cassegrain telescope: A type of reflecting telescope.
Key Concept: Current (I) from a cell with EMF (E) and internal resistance (r) through external resistance (R_ext): I = E / (R_ext + r).
Problem: A cell gives 0.25 A through 5 Ω, and 0.5 A through 2 Ω. Calculate the EMF (E) of the cell.
Solution:
Equation 1: 0.25 = E / (5 + r) => E = 0.25(5 + r)
Equation 2: 0.5 = E / (2 + r) => E = 0.5(2 + r)
Equating E: 0.25(5 + r) = 0.5(2 + r)
1.25 + 0.25r = 1 + 0.5r
0.25 = 0.25r => r = 1 Ω.
Substitute r=1Ω into E = 0.25(5 + r):
E = 0.25(5 + 1) = 0.25 * 6 = 1.5 V.
Key Concepts:
Power: P = V² / R.
Resistance of a wire: R = ρL / A.
Area of wire: A = πD² / 4.
Problem: A nichrome wire (L=10m, P=160W, V=40V, ρ=10⁻⁶ Ωm). Calculate its diameter (D).
Solution:
Calculate R: R = V² / P = (40)² / 160 = 1600 / 160 = 10 Ω.
Calculate A: R = ρL / A => 10 = (10⁻⁶ * 10) / A => A = 10⁻⁵ / 10 = 10⁻⁶ m².
Calculate D: A = πD² / 4 => 10⁻⁶ = πD² / 4 => D² = (4 * 10⁻⁶) / π
D = √[(4 * 10⁻⁶) / π] = (2 * 10⁻³) / √π ≈ 1.128 * 10⁻³ m
D ≈ 1.12 mm.
Key Concept: The final energy level (n_f) determines the spectral series.
Lyman Series: n_f = 1
Balmer Series: n_f = 2
Paschen Series: n_f = 3
Brackett Series: n_f = 4
Pfund Series: n_f = 5
Problem: An electron in a hydrogen atom jumps from n=4 to n=2. To which spectral series does the emission line belong?
Answer: Since the electron transitions to n=2, the emission line belongs to the Balmer Series.
Problem: Which statement is correct regarding electromagnetic radiation?
Statements and Analysis:
X-rays are suitable for radar systems and aircraft navigation.
Incorrect. Microwaves are used for radar.
Water molecules readily absorb infrared radiation, and their thermal motion increases.
Correct. Infrared radiation increases molecular kinetic energy, causing heating. This is fundamental to microwave ovens.
Microwaves are produced in Coolis tubes.
Incorrect. Coolis tubes produce X-rays.
Gamma radiations are generally due to electron transition.
Incorrect. Gamma rays originate from nuclear transitions.
Key Concept: De Broglie Wavelength: λ = h / √(2mQV), where Q is charge, V is potential difference.
Problem: Proton (1H1) and Tritium (1H3) are accelerated from rest through potential difference V. Find the ratio of their de Broglie wavelengths.
Solution:
Proton (1H1): Mass (m₁) ≈ m, Charge (Q₁) = Q.
Tritium (1H3): Mass (m₂) ≈ 3m, Charge (Q₂) = Q.
Ratio of wavelengths:
λ₁ / λ₂ = [h / √(2m₁Q₁V)] / [h / √(2m₂Q₂V)]
Since h, Q, V are constant:
λ₁ / λ₂ = √(m₂ / m₁) = √(3m / m) = √3.
Problem: The barrier potential of a PN junction depends on:
Type of semiconductor material
Amount of doping
Temperature
Answer: The barrier potential of a PN junction depends on all three factors:
Type of semiconductor material: Different materials have different energy band gaps.
Amount of doping: Affects the width of the depletion region.
Temperature: Higher temperature provides more thermal energy to carriers.
Key Concept: Frequency of revolution (cyclotron frequency) in a transverse magnetic field: f = qB / (2πm).
Problem: An electron moves in a circular path in a transverse magnetic field. Given q/m = 1.76 x 10¹¹ C/kg and B = 3.57 x 10⁻² T. Calculate the frequency of revolution.
Solution:
f = (1.76 * 10¹¹ C/kg) * (3.57 * 10⁻² T) / (2π)
f ≈ (6.28 * 10⁹) / (6.28) Hz
f ≈ 1 * 10⁹ Hz = 1 Gigahertz (GHz).
Key Concept: Bohr's model describes electron orbits in hydrogen-like atoms.
Problem: According to Bohr's model, which statements are correct for the orbiting electron?
Radius of the orbiting electron is directly proportional to n.
Speed of the orbiting electron is inversely proportional to n.
Magnitude of the total energy of the orbiting electron is directly proportional to 1/n².
Radius of the orbiting electron is directly proportional to n².
Analysis:
Statement 1: Incorrect (r ∝ n²).
Statement 2: Correct (v ∝ 1/n).
Statement 3: Correct (|E| ∝ 1/n²).
Statement 4: Correct (r ∝ n²).
Conclusion: Statements 2, 3, and 4 are correct.
Key Concept: In a steady-state DC circuit, a capacitor acts as an open circuit (blocks current).
Problem: In a DC circuit with a capacitor and two resistors, a 5V battery, and a switch, a micro-ammeter reads 20 microamperes when the switch is closed. Determine the value of resistance R.
Solution:
At steady state, the capacitor blocks current, so current flows only through the resistive path.
Given: V = 5 V, I = 20 µA = 20 * 10⁻⁶ A.
Using Ohm's Law (V = IR):
R = V / I = 5 V / (20 * 10⁻⁶ A) = 0.25 * 10⁶ Ω
R = 250 kilo-ohms (kΩ).
Key Concept: Terminal potential difference (V) when a current (I) is drawn from a cell with EMF (E) and internal resistance (r): V = E - IR.
Problem: How is the variation of terminal potential difference (V) of a cell with current (I) correctly represented graphically?
Analysis:
The equation V = E - IR is a linear equation (y = mx + c), where:
y = V (terminal potential difference)
x = I (current)
c = E (Y-intercept, the EMF when I=0)
m = -R (slope)
Since internal resistance (R) is always positive, the slope (-R) is always negative.
Therefore, the graph is a straight line with a negative slope and a positive Y-intercept (E).
Key Concept: Gauss's Law for Magnetism states that the net magnetic flux through any closed surface is always zero (Φ_B = 0).
Problem: Magnetic flux through any closed surface around a magnet is always zero. What is the correct reason for this?
Answer: The fundamental reason is that magnetic monopoles do not exist. Magnets are always dipoles, meaning they always have both a North and a South pole. For any closed surface enclosing a magnet, every magnetic field line entering the surface also exits it, resulting in zero net flux.
Key Concept: Resonant frequency (f₀) in an LCR circuit: f₀ = 1 / (2π√(LC)).
Problem: To reduce the resonant frequency in an LCR circuit, what action should be taken?
Analysis:
To reduce f₀, the term √(LC) must increase. This means either L or C (or both) must increase.
Adding another capacitor in parallel: When capacitors are in parallel, the total capacitance (C_eq = C₁ + C₂) increases. An increase in C leads to a decrease in f₀. (Correct)
Reducing generator frequency: Changes operating frequency, not resonant frequency.
Removing iron core from inductor: Decreases L, thus increases f₀.
Removing dielectric from the capacitor: Decreases C, thus increases f₀.
Answer: Adding another capacitor in parallel to the first will reduce the resonant frequency.
| CUET 2026 Exam Analysis 11 May | CUET 2026 Exam Analysis 12 May |
Students are advised to follow the instructions given below-
Focus on practice is paramount in physics preparation.
Most questions covered are from CUET previous shifts or expected patterns.
Detailed stepwise solutions for electric flux, LCR RMS current, galvanometer-ammeter conversion, battery combinations, capacitor networks, optics problems, and more were provided.
Emphasis on conceptual clarity: eg, series and parallel battery combinations, magnetic flux, critical angle, and Bohr model relationships.
Statistical data on student response accuracy per question ranges from 15% to 100%, indicating varying difficulty and student preparedness.
Realistic motivational insights regarding student anxiety, study approach, and socio-economic background were also addressed.
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