The 2013 paper gives electromagnetism an unusually large share, keeps mechanics on its classic track, and keeps thermodynamics gentle; scenarios come mostly from labs and daily life. 40 questions in 45 minutes, calculators allowed, Division 1 / Division 2 scored separately. Scan for the paper and answers.
The 25 online practice questions start instantly; the full past-paper & answers PDF is available free from an advisor via the QR code — it is not a direct download on this page.2013 Physics Bowl paper overview and exam highlights.
The 2013 paper is a released year. Its standout feature is a heavier-than-usual electromagnetism block, with solid coverage of circuits, magnetic forces and induction. Mechanics still leads in share, and thermodynamics stays at its friendly, routine level.
The format is unchanged: 40 multiple-choice questions in 45 minutes, points for correct answers, nothing off for wrong ones, calculators allowed, paper in English. Division 1 (first-year students and beginners, no calculus) and Division 2 (second-year and AP Physics C students) are ranked and awarded separately, and you may enter only one.
Given the strong electromagnetism share, it pays to map series-parallel reduction, magnetic forces and induction onto one hand-drawn chart. Scan the code for the 2013 paper and answers, then use the 25 original practice questions here to check every topic.
2013 Physics Bowl main topic areas, weights and emphasis.
Kinematics calculations, projectiles and rotational motion share the stage.
A heavy EM year: circuits, magnetic forces, transformers and induction all covered.
Sound-wave math, lens images and basic interference.
Mixing calorimetry and gas laws: short steps, friendly difficulty.
Light touches of atomic structure, half-life and basic relativity.
2013 Physics Bowl-style mock questions (Basic · Medium · Hard) — submit to grade and view step-by-step solutions.
A train covers 150 km at a steady pace in 2.5 h. What is its average speed?
Correct answer: B
v = s/t = 150/2.5 = 60 km/h. Answer B. Core: average speed = total distance over total time.A coin is dropped from rest from a 45 m balcony (g = 10 m/s2, no air resistance). How long does it take to fall?
Correct answer: B
From h = ½gt2, t = √(2h/g) = 3 s. Answer B. Core: free fall takes t = √(2h/g).A small lamp runs at 6 V with a current of 0.5 A. What is the resistance of its filament?
Correct answer: D
R = U/I = 6/0.5 = 12 Ω. Answer D. Core: R = U/I.A 2000 W space heater runs for 30 s. How much energy does it consume?
Correct answer: D
E = Pt = 2000×30 = 60000 J = 6×104 J. Answer D. Core: energy E = Pt.0.2 kg of water at 80 °C is poured into 0.3 kg of water at 20 °C. Ignoring heat loss, what is the final temperature?
Correct answer: A
Heat lost equals heat gained: 0.2×(80-T) = 0.3×(T-20), giving T = 44 °C. Answer A. Core: mixing problems balance heat lost against heat gained.A crown has a mass of 400 g and a volume of 50 cm3. What is its average density?
Correct answer: D
ρ = m/V = 400/50 = 8 g/cm3. Answer D. Core: density = mass over volume.Thunder arrives 3 s after the lightning flash. If sound travels at 340 m/s, how far away is the storm?
Correct answer: E
Light is effectively instant: d = vt = 340×3 = 1020 m. Answer E. Core: d = vt.A carbon-14 nucleus has mass number 14 and 6 protons. How many neutrons does it contain?
Correct answer: E
Neutrons = mass number - protons = 14 - 6 = 8. Answer E. Core: N = A - Z.A motor does 3000 J of work in 12 s. What is its average power?
Correct answer: D
P = W/t = 3000/12 = 250 W. Answer D. Core: power = work over time.A 5 μF capacitor is charged by a 6 V battery. How much charge sits on one plate?
Correct answer: D
Q = CU = 5×10-6×6 = 3×10-5 C = 30 μC. Answer D. Core: Q = CU.A javelin is thrown at 20 m/s at 45° over level ground (g = 10 m/s2). How far from the thrower does it land?
Correct answer: A
At 45° the range is maximal: R = v02/g = 400/10 = 40 m. Answer A. Core: at 45°, R = v2/g.An astronaut weighs 400 N on the surface of a planet. After rising to a height equal to the planet radius, roughly what gravitational force acts on him?
Correct answer: B
Gravity falls with the square of distance: doubling r gives F/4 = 100 N. Answer B. Core: F ∝ 1/r2.A 0.2 kg glider on a frictionless air track is attached to a horizontal spring of stiffness 80 N/m and moves in simple harmonic motion. What is the oscillation frequency?
Correct answer: E
Simple harmonic motion gives f = (1/2π)√(k/m) = (1/2π)×√400 ≈ 3.2 Hz. Answer E. Core: SHM frequency f = (1/2π)√(k/m).A 0.4 kg ball hits a wall head-on at 15 m/s and rebounds at 10 m/s. What is the magnitude of the impulse the wall gives the ball?
Correct answer: E
Taking rebound as positive: J = mΔv = 0.4×(15+10) = 10 N·s. Answer E. Core: impulse equals momentum change; a reversal makes the speeds add.A 12 V battery feeds a 2 Ω resistor in series with a parallel pair of 6 Ω and 3 Ω. What current flows through the 3 Ω resistor?
Correct answer: E
The pair gives 2 Ω, the total is 4 Ω, so the main current is 3 A; the pair sees 3×2 = 6 V, hence I = 6/3 = 2 A. Answer E. Core: reduce the circuit first, then step back into the branch.An ideal transformer has 500 primary turns connected to 220 V AC and 100 secondary turns. What is the secondary voltage?
Correct answer: C
U2 = U1×N2/N1 = 220×100/500 = 44 V. Answer C. Core: transformer voltage scales with the turn ratio.An electron (charge 1.6×10-19 C) moves at 2×106 m/s perpendicular to a uniform 0.3 T magnetic field. What force does the field exert on it?
Correct answer: A
F = qvB = 1.6×10-19×2×106×0.3 = 9.6×10-14 N. Answer A. Core: F = qvB for motion perpendicular to the field.An object is placed 10 cm from a converging lens of focal length 20 cm. What kind of image forms?
Correct answer: C
With u < f: 1/v = 1/20 - 1/10 = -1/20, so v = -20 cm (virtual) with magnification 2. Answer C. Core: inside the focal length a converging lens acts as a magnifier.Light of wavelength 500 nm passes through double slits 2 μm apart. At what angle does the first bright fringe appear?
Correct answer: C
Bright fringes obey d sinθ = mλ: sinθ = 5×10-7/2×10-6 = 0.25, so θ ≈ 14.5°. Answer C. Core: double-slit maxima satisfy d sinθ = mλ.A fixed mass of ideal gas is compressed at constant temperature to half its volume, starting from 1×105 Pa. What is the final pressure?
Correct answer: A
At constant temperature PV is fixed, so halving the volume doubles the pressure to 2×105 Pa. Answer A. Core: at fixed temperature, P ∝ 1/V.A flywheel is a uniform disk (I = ½MR2) of mass 4 kg and radius 0.5 m. A steady 2 N·m torque spins it up from rest. What is its rotational kinetic energy after 5 s?
Correct answer: E
I = ½×4×0.52 = 0.5 kg·m2, α = τ/I = 4 rad/s2, ω = 20 rad/s, so KE = ½Iω2 = 100 J. Answer E. Core: α = τ/I first, then KE = ½Iω2.A 0.4 m metal rod slides at 5 m/s along horizontal rails, cutting across a 0.25 T field, with a total loop resistance of 0.1 Ω. What power is dissipated in the loop?
Correct answer: C
Motional EMF ε = BLv = 0.25×0.4×5 = 0.5 V, current I = ε/R = 5 A, so P = I2R = 25×0.1 = 2.5 W. Answer C. Core: first ε = BLv, then P = ε2/R.A string fixed at both ends is 0.5 m long and carries transverse waves at 300 m/s. How many standing-wave modes have frequencies at or below 1500 Hz?
Correct answer: A
The fundamental is f1 = v/2L = 300 Hz, so fn = 300n ≤ 1500 gives n ≤ 5, i.e. 5 modes. Answer A. Core: fixed-string modes satisfy fn = n·v/2L.A radioisotope has a half-life of 5 days. Starting from 96 g, how much remains after 15 days?
Correct answer: B
15 days = 3 half-lives: 96 → 48 → 24 → 12 g. Answer B. Core: each half-life halves what is left.A spaceship of proper length 120 m flies past a station at 0.8c. What length does a station observer measure?
Correct answer: C
Length contraction: L = L0√(1-0.82) = 120×0.6 = 72 m. Answer C. Core: L = L0/γ along the direction of motion.Unified Physics Bowl specs, consistent across years.
Division 1 is for first-year physics students (no calculus); Division 2 is for second-year and AP Physics C students. The two divisions are ranked and awarded separately — students must choose one and cannot take both. Pick based on your level; our advisor can help.
Four steps · Overview / Topics / Practice / Prep
Read the 2013 Physics Bowl overview and format specs to grasp the year’s style.
Review the key topics and weights, and locate your weak areas.
Complete the 25 mock questions; submit for auto-grading and right/wrong marks.
Open the step-by-step solutions, learn from mistakes, and scan for full papers to push for national and global rankings.
Prep tips and score-boosting advice for the 2013 Physics Bowl.
With EM so prominent, invest early: one drill set each for series-parallel reduction, magnetic-force directions, and Faraday law, so this block becomes an engine of points rather than a leak.
Redraw the equivalent circuit before any calculation to dodge most errors. The habit of reduce, compute, then step back into branches turns hard circuit questions into routines.
Thermodynamics and modern physics are small and formulaic here: one main line each for calorimetry, gas laws and half-life halving. Collect these points first in the exam.
Learn the high-frequency terms such as friction, resistor and photon ahead of time, and circle the numbers and conditions while reading. Misreads from unfamiliar vocabulary are the most common hidden loss for Chinese candidates.
Scan for the 2013 paper and answers, sit a strictly timed attempt, tally accuracy by topic, and repair weak areas with the matching practice questions here; a second attempt should show a clear gain.
Frequent questions about the 2013 Physics Bowl papers and answers.
Scan to add the advisor for 2013 Physics Bowl past papers, answer keys and solutions, plus a custom prep plan.
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