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Al Mustafa Model High School

Solved Model Paper (Practice) — Session 2026–2027

Class10 (Matric – Science) SubjectPhysics
Paper PatternBISE Lahore Total Marks60
Time (Objective)15 Minutes Time (Subjective)1 Hour 45 Minutes
Name:  Roll No:  Section:  
Note: This is a practice model paper prepared by the school. All questions are original and are set from the Class 10 Punjab textbook. Complete handwritten-style solutions are given after the paper.

SECTION A — OBJECTIVE Marks: 12  |  Time: 15 Minutes

Choose the correct option. Each question carries 1 mark.

  1. The audible frequency range for a normal human ear is:
    (A) 2 Hz to 200 Hz(B) 20 Hz to 20,000 Hz(C) 200 Hz to 200,000 Hz(D) 20 Hz to 2,000 Hz
  2. The pitch of a sound depends upon its:
    (A) amplitude(B) wavelength(C) frequency(D) speed
  3. The focal length of a plane mirror is:
    (A) zero(B) 25 cm(C) 50 cm(D) infinity
  4. The power of a lens of focal length 50 cm is:
    (A) 0.5 dioptre(B) 1 dioptre(C) 2 dioptres(D) 5 dioptres
  5. The SI unit of electric charge is:
    (A) ampere(B) volt(C) coulomb(D) ohm
  6. According to Ohm’s law:
    (A) V = I/R(B) V = IR(C) V = R/I(D) V = I²R
  7. Two resistors of 4 Ω and 6 Ω are connected in series. Their equivalent resistance is:
    (A) 2.4 Ω(B) 10 Ω(C) 24 Ω(D) 0.4 Ω
  8. An electric motor converts:
    (A) mechanical energy into electrical energy(B) electrical energy into mechanical energy(C) heat energy into electrical energy(D) electrical energy into light energy only
  9. In an AND gate, the output is 1 only when:
    (A) any one input is 1(B) both inputs are 1(C) both inputs are 0(D) the two inputs are different
  10. In an optical fibre, the light signal travels through the core by:
    (A) refraction(B) diffraction(C) total internal reflection(D) dispersion
  11. The number of protons present in the nucleus of an atom is called:
    (A) mass number(B) atomic number(C) neutron number(D) isotope number
  12. Which of the following radiations has the highest penetrating power?
    (A) alpha rays(B) beta rays(C) gamma rays(D) all have equal penetrating power

SECTION B — SUBJECTIVE Marks: 48  |  Time: 1 Hour 45 Minutes

PART I — SHORT QUESTIONS

Attempt any FIVE (5) parts from each question. Each part carries 2 marks.

Q.2(5 × 2 = 10)
  1. How are pitch and loudness of a sound related to the properties of the wave producing it?
  2. What is an echo? Write the condition for hearing a distinct echo.
  3. Define ultrasound and write two of its uses.
  4. Sound cannot travel through vacuum. Why?
  5. Define refractive index. What is its unit?
  6. Differentiate between a real image and a virtual image.
  7. Write two conditions necessary for total internal reflection.
  8. Define the power of a lens. A lens has power +2 D; find its focal length and nature.
Q.3(5 × 2 = 10)
  1. State Coulomb’s law of electrostatics.
  2. Define electric field intensity and write its unit.
  3. Define capacitance of a capacitor and write its unit.
  4. What happens to the total capacitance when capacitors are connected in series? Write the formula.
  5. Define resistivity. On what factors does it depend?
  6. Why is a voltmeter always connected in parallel in a circuit?
  7. Define electric power and write its formulas.
  8. What is the purpose of a fuse in a domestic electric circuit?
Q.4(5 × 2 = 10)
  1. What is electromagnetic induction? State Faraday’s law of electromagnetic induction.
  2. Why does a transformer not work with direct current (DC)?
  3. Differentiate between analogue and digital signals.
  4. Write the truth table of an AND gate.
  5. What is meant by ICT? Write its full form.
  6. Write the names of the main components of a communication system.
  7. What are isotopes? Give one example.
  8. Define the half-life of a radioactive element.

PART II — LONG QUESTIONS

Attempt any TWO (2) questions. Each question carries 9 marks.

Q.5(5 + 4 = 9)
  1. State Coulomb’s law and use it to calculate the force between two point charges of 3 µC and 4 µC placed 30 cm apart in air.
  2. On what factors does the capacitance of a parallel plate capacitor depend?
Q.6(5 + 4 = 9)
  1. Describe the construction and working of a transformer.
  2. A step-down transformer changes 220 V into 11 V. If the primary coil has 4,400 turns, find the number of turns in the secondary coil.
Q.7(5 + 4 = 9)
  1. Compare alpha, beta and gamma radiations with respect to their nature, charge, mass, penetrating power and ionizing power.
  2. The half-life of a radioactive element is 5 days. How much of an 80 g sample of it will remain after 15 days?

✓ SOLUTIONS — In a Topper’s Neat Hand

Study how each answer is written: short, to the point, with formulas and units.

Section A — Objective (Answer Key)

1. (B)   2. (C)   3. (D)   4. (C)   5. (C)   6. (B)   7. (B)   8. (B)   9. (B)   10. (C)   11. (B)   12. (C)

Remember: pitch → frequency, power of lens P = 1/f (metres), series resistance simply adds up, and gamma rays penetrate the most.

Q.2 — Short Questions (Sound & Geometrical Optics)

(i) Pitch depends upon frequency: higher the frequency, higher the pitch. Loudness depends upon amplitude: greater the amplitude, louder the sound.

(ii) An echo is the repetition of sound caused by its reflection from a distant surface like a wall or cliff. For a distinct echo, the surface must be at least 17 m away, so the reflected sound reaches us 0.1 s after the original sound.

(iii) Sound waves of frequency higher than 20,000 Hz are called ultrasound. Uses: in SONAR to measure sea depth, and in medical scanning.

(iv) Sound is a mechanical wave and needs a material medium to travel. Vacuum has no particles to carry the vibrations, so sound cannot travel through it.

(v) Refractive index is the ratio of the speed of light in vacuum to its speed in the medium. It has no unit, being a ratio.

(vi) A real image is formed by the actual meeting of rays, is inverted, and can be taken on a screen. A virtual image is formed where rays only appear to meet, is erect, and cannot be taken on a screen.

(vii) For total internal reflection: (1) light must pass from a denser to a rarer medium; (2) the angle of incidence must be greater than the critical angle.

(viii) Power of a lens is the reciprocal of its focal length in metres, P = 1/f. For P = +2 D: f = 1/2 = 0.5 m = 50 cm. Positive sign means it is a convex lens.

Q.3 — Short Questions (Electrostatics & Current Electricity)

(i) Coulomb’s law: the force between two point charges is directly proportional to the product of the charges and inversely proportional to the square of the distance between them. F = k q1q2/r2.

(ii) Electric field intensity is the force experienced by a unit positive test charge at that point, E = F/q. Its unit is newton per coulomb (N/C).

(iii) Capacitance is the ratio of charge on a plate to the potential difference between the plates, C = Q/V. Its unit is the farad (F).

(iv) In series, total capacitance decreases and becomes less than the smallest capacitor: 1/C = 1/C1 + 1/C2.

(v) Resistivity is the resistance of a conductor of unit length and unit cross-sectional area, ρ = RA/l. It depends on the nature of the material and its temperature only.

(vi) A voltmeter measures potential difference between two points, so it is joined across them, i.e. in parallel. Its very high resistance keeps the circuit undisturbed.

(vii) Electric power is the rate of conversion of electrical energy: P = VI = I2R = V2/R. Its unit is the watt.

(viii) A fuse is a safety device with a low-melting-point wire. On excess current it melts and breaks the circuit, protecting appliances and wiring from damage and fire.

Q.4 — Short Questions (Electromagnetism, Electronics, ICT & Nuclear Physics)

(i) The production of induced EMF in a coil due to change of magnetic flux through it is electromagnetic induction. Faraday’s law: the induced EMF is directly proportional to the rate of change of magnetic flux.

(ii) A transformer needs a continuously changing flux for mutual induction. DC produces a steady flux, so no EMF is induced in the secondary coil.

(iii) An analogue signal varies continuously with time, e.g. a microphone output. A digital signal takes only two values, 0 and 1, as used in computers.

(iv) Truth table of AND gate:

ABX = A.B
000
010
100
111

(v) ICT stands for Information and Communication Technology — the technology used to communicate, store and process information, e.g. phones, radio, TV and the internet.

(vi) Components of a communication system: information source, transmitter, transmission medium (channel), receiver, and the final user.

(vii) Isotopes are atoms of the same element with the same atomic number but different mass numbers. Example: hydrogen — protium, deuterium, tritium.

(viii) Half-life is the time in which half of the atoms of a radioactive sample decay, i.e. its amount/activity falls to one half.

Q.5 — Coulomb’s Law & Capacitance (Long)

(a) Coulomb’s law: F = k q1q2/r2, k = 9 × 109 N m2/C2.

Given: q1 = 3 µC = 3 × 10−6 C,   q2 = 4 µC = 4 × 10−6 C,   r = 30 cm = 0.30 m.

F = (9 × 109 × 3 × 10−6 × 4 × 10−6) / (0.30)2 = (108 × 10−3) / 0.09 = 1.2 N. Both charges are of the same sign, so the force is repulsive.

(b) Capacitance of a parallel plate capacitor increases with the area of the plates, decreases as the plate separation increases, and increases when a dielectric is placed between the plates.

Q.6 — The Transformer (Long)

(a) A transformer has two coils of insulated copper wire — the primary and the secondary — wound on a laminated soft-iron core. AC in the primary coil produces a continuously changing magnetic flux in the core. This changing flux links the secondary coil and, by mutual induction, induces an alternating EMF in it. The voltages follow Vs/Vp = Ns/Np.

(b) Ns = Np × Vs/Vp = 4,400 × 11/220 = 4,400 / 20 = 220 turns.

Q.7 — Radiations & Half-Life (Long)

(a) Alpha particles are helium nuclei (2 protons + 2 neutrons), charge +2e: strongest ionizing power, weakest penetration — stopped by paper. Beta particles are fast electrons, charge −1e: moderate ionization and penetration — stopped by thin aluminium. Gamma rays are electromagnetic waves, no charge or mass: weakest ionization, strongest penetration — reduced by thick lead.

(b) Half-lives in 15 days = 15 / 5 = 3. Remaining mass = 80 × (1/2)3 = 80 / 8 = 10 g. (80 g → 40 g → 20 g → 10 g.)

Al Mustafa Model High School — Solved Model Paper (Practice) · Class 10 Physics · Generated for SchoolRaabta Paper Studio · All questions are original practice questions based on the Punjab textbook.