CBSE Class 12 Physics Half-Yearly Exam 2025-26: Most Important Numerical Questions From All Chapters

Important Numerical Questions For CBSE Class 12 Half-Yearly Exam: To score well in the Physics exam, students also need a deep understanding of the numerical questions. Practising consistently and getting a clear conceptual grasp of the concepts is important to understanding the subject. This article is designed in a way that it helps the students with the important numerical questions for class 12th-class Physics exam. 

CBSE Class 12 Physics Half-Yearly Exam 2025-26: Important Numerical Questions

Get here the important numerical questions along with their answers to practise for the exam: 

Chapter 1: Electric Charges and Fields

1. Given a uniform electric field E→= 4×103i^ N/C. Find the flux of this field through a square of 5 cm on a side whose plane is parallel to the Y-Z plane. What would be the flux through the same square if the plane makes a 30° angle with the x-axis?

2. A sphere S1 of radius r1 encloses a net charge Q. If there

is another concentric sphere S2 of radius r2 (r2 > r1) enclosing charge 2Q, find the ratio of the electric flux through S1 and S2. How will the electric flux through sphere S1 change if a medium of dielectric constant K is introduced in the space inside S2 in place of air?

Chapter 2: Electrostatic Potential and Capacitance

1. A capacitor of unknown capacitance is connected across a battery of V volts. The charge stored is 300 μC. When the potential is reduced by 100 V, the charge becomes 100 μC. Find the battery voltage and capacitance.

2. A parallel plate capacitor has square plates of side 5 cm, separated by 1 mm. (a) Calculate its capacitance. (b) If connected to a 10 V battery, find the charge stored.

3. Three capacitors of 3,3,6 μF are connected in series to a 10 V source. Find the charge on the 3μF capacitor.

4. A slab of dielectric constant K and thickness d/2 is introduced between plates of a parallel plate capacitor (plate separation d). Find the new capacitance.

Chapter 3: Current Electricity

1. A wire of resistance RRR is cut into n equal parts. These are connected (a) in series and (b) in parallel. Find the effective resistance.

2. Two cells of emf 2 V and 4 V and internal resistances 1 Ω and 2 Ω, respectively, are connected in parallel. Calculate the effective emf and internal resistance.

3. A battery of emf 12 V and internal resistance 0.5 Ω is connected to a 5 Ω resistor. Calculate current, terminal voltage, and power dissipated.

4. In a meter bridge, the null point is found at 40 cm. If known resistance is 2 Ω, find the unknown resistance.

Chapter 4: Moving Charges & Magnetism

1. A current of 2 A flows through a circular coil of radius 0.1 m and 100 turns. Find the magnetic field at the centre.

2. Calculate the force between two parallel conductors 1 m long, placed 0.1 m apart, each carrying 10 A in the same direction.

3. A proton enters a uniform magnetic field of 0.01 T with velocity 2×106m/s perpendicular to the field. Find the radius of the path.

4. A galvanometer of resistance 50 Ω gives full-scale deflection at 5 mA. Find the resistance required to convert it into an ammeter of range 5 A.

Chapter 6–7: EMI & Alternating Current

1. A coil of self-inductance 2 H is connected to a 220 V AC supply at 50 Hz. Find reactance and rms current.

2. A 200 V AC is applied across a 50 Ω resistor. Find the rms current and the power dissipated.

3. In an LCR circuit, L = 0.1 H, C = 25 μF, R = 100 Ω. Find resonant frequency and impedance at resonance.

4. A transformer reduces voltage from 2200 V to 220 V. If the primary has 1000 turns, find the turns in the secondary.

Chapter 9–10: Optics

1. An object is placed 20 cm from a convex lens of focal length 15 cm. Find the position and nature of the image.

2. A convex lens of focal length 10 cm is in contact with a concave lens of focal length 20 cm. Find the focal length of the combination.

3. The central maximum of a single slit diffraction pattern is 2 cm wide when the screen is 2 m away. If the slit width is 0.2 mm, find the wavelength.

4. In Young’s double slit experiment, fringes are 1 mm wide with the screen 1 m away. If the separation of slits is 0.5 mm, find the wavelength.

Chapter 11: Dual Nature

1. Calculate the maximum kinetic energy and stopping potential for photoelectrons emitted by light of wavelength 300 nm (Work function = 2 eV).

2. If the wavelength of de-Broglie waves of an electron is 1 Å, find its momentum and kinetic energy.

Chapter 12: Atoms

1. Using Bohr’s model, find the energy of an electron in the second orbit of hydrogen.

2. Calculate the wavelength of the first line of the Balmer series of hydrogen.

Chapter 13: Nuclei

1. Calculate the binding energy per nucleon of 56Fe. (Mass of atom = 55.9349 u, H = 1.0078 u, n = 1.0087 u).

2. A radioactive nucleus has a half-life of 10 days. What fraction remains after 30 days?

Students can take a look at these numericals, as we will be providing the correct answers soon in this PDF. 

Check the solutions below: 

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