Physics: Mechanics, Electricity and Optics for AEEE
AEEE Physics tests conceptual understanding and one-step numerical fluency across mechanics, properties of matter, thermodynamics, oscillations and waves, electrostatics, current electricity, magnetism, optics and modern physics. Most items are solvable in under a minute with the right formula; the difficulty lies in choosing the right model and sign convention.
Core rules
- Kinematics: v = u + at, s = ut + ½at², v² = u² + 2as, valid only for constant acceleration.
- Work–energy theorem: net work equals change in kinetic energy; mechanical energy is conserved only when non-conservative forces do no work.
- Static friction is self-adjusting up to f(max) = μN; never set f = μN unless the body is on the verge of slipping.
- Capacitors in series add as reciprocals, in parallel directly: 1/C = 1/C₁ + 1/C₂; C = C₁ + C₂.
- Lens/mirror formula 1/v − 1/u = 1/f (lens) with the Cartesian sign convention; magnification m = v/u.
Worked example
A 3 μF and a 6 μF capacitor are connected in series across a 12 V battery. Find the charge on each. Series capacitance: 1/C = 1/3 + 1/6 = 3/6, so C = 2 μF. Charge: Q = CV = 2 μF × 12 V = 24 μC. In series the charge is identical on both capacitors, so each holds 24 μC; the voltages divide as 8 V and 4 V, which sum to 12 V. This voltage check catches most arithmetic slips.
Traps that cost marks
- Mixing g = 9.8 m/s² and g = 10 m/s² within one problem.
- Forgetting that the horizontal velocity of a projectile stays constant while only the vertical component changes.
- In optics, dropping the negative sign on u or on the focal length of a concave lens.
- Confusing rms and peak values of AC: V(rms) = V(peak)/√2.
- Using cm instead of m in force, energy or capacitance formulas.