SPH4U practice exam: Grade 12 Physics questions and exam rules

Each daily paper has 8 original questions worth 25 to 35 marks, and you need both for SPH4U. The Grade 12 Physics (SPH4U) paper covers circular motion and gravitational, electric and magnetic fields; its thermal physics, capacitor, simple harmonic motion and nuclear questions go beyond SPH4U. The Grade 11 Physics paper adds momentum, diffraction and the photoelectric effect. Neither covers special relativity.

How the SPH4U exam counts in 2026-27

In Grade 12 science in Ontario, your final mark is now 65% classroom work, a 25% written exam, and 10% attendance and participation, with the exam written in your board's exam period. The prerequisite for SPH4U is Grade 11 university preparation physics (SPH3U). These figures come from the Ministry of Education's September 2026 update to Growing Success.

What's on the SPH4U exam: the strands

• Dynamics: forces and motion, including circular motion.
• Energy and momentum: conservation of energy and momentum, and collisions.
• Gravitational, electric and magnetic fields.
• The wave nature of light: interference and diffraction.
• Revolutions in modern physics: quantum mechanics and special relativity.
• Scientific investigation skills and career exploration run through every unit.

SPH4U practice exam questions with answers

We wrote these for this page, one from each main strand. Use g = 9.8 m/s², G = 6.67 × 10⁻¹¹ N m²/kg², and Earth's mass 5.97 × 10²⁴ kg and radius 6.37 × 10⁶ m.

1. Dynamics. A car rounds a flat curve of radius 50 m at 15 m/s. What is its centripetal acceleration, and what is the least coefficient of friction that stops it skidding? Answer: a = v² ÷ r = 225 ÷ 50 = 4.5 m/s². Friction provides the centripetal force, so μmg = ma and μ = 4.5 ÷ 9.8 ≈ 0.46. Mass cancels. The Circular Motion Calculator checks these.

2. Energy and momentum. A 2.0 kg cart at 6.0 m/s collides elastically head-on with a 1.0 kg cart at rest. Find both velocities afterward. Answer: for an elastic collision with the second cart at rest, v₁ = (m₁ − m₂)u ÷ (m₁ + m₂) = 2.0 m/s and v₂ = 2m₁u ÷ (m₁ + m₂) = 8.0 m/s. Check: momentum is 12 kg m/s before and after (4.0 + 8.0), and kinetic energy is 36 J both times. Try a collision question from our Laws of Motion course, then press Mark.

3. Gravitational fields. Find the gravitational field strength and the orbital speed for a satellite 400 km above Earth. Answer: r = 6.37 × 10⁶ + 4.0 × 10⁵ = 6.77 × 10⁶ m. g = GM ÷ r² ≈ 8.69 N/kg, and setting gravity equal to the centripetal force gives v = √(GM ÷ r) ≈ 7.67 km/s, about one orbit every 92 minutes. Use the distance from Earth's centre, not the altitude. Try orbits in the Orbit Simulator.

4. The wave nature of light. Light of wavelength 600 nm passes through two slits 0.25 mm apart onto a screen 2.0 m away. How far apart are the bright fringes? Answer: Δy = λL ÷ d = (600 × 10⁻⁹)(2.0) ÷ (0.25 × 10⁻³) = 4.8 mm. Convert nanometres and millimetres to metres first. See the pattern in the Wave Interference simulator.

5. Special relativity. A particle with a lifetime of 2.0 μs at rest moves at 0.80c. How long does it last as measured in the lab? Answer: γ = 1 ÷ √(1 − 0.80²) = 1 ÷ 0.6 ≈ 1.67, so the lab measures 2.0 × 1.67 ≈ 3.3 μs. Moving clocks run slow, so the lab time is always the longer one.

Use the daily papers as practice exams

1. Alternate the SPH4U and SPH3U papers, and work to the suggested time, 35 to 45 minutes.
2. Skip the questions outside SPH4U listed at the top of this page.
3. Practise special relativity separately, because neither paper covers it.
4. Mark each paper and note which strand each lost mark belongs to.

Common SPH4U mistakes

• Using altitude instead of distance from Earth's centre in gravitation.
• Treating centripetal force as an extra force: it is provided by friction, tension, gravity or another real force.
• Assuming kinetic energy is conserved in every collision.
• Leaving wavelengths in nanometres in the fringe equation.
• Swapping proper time and dilated time in relativity.

Read next

Canada · Grade 12SCH4U Practice Exam: Grade 12 Chemistry Questions, AnswersAn SCH4U practice exam: free Grade 12 Chemistry questions on organic, structure, calorimetry, equilibrium and cells, and how the 2026-27 exam counts.