Bulb Brightness
Predict which bulbs glow brighter in series and parallel circuits.
Resistor Circuit Trainer
Find equivalent resistances, currents and voltages step by step.
Impedance Curves
Read R, L and C off the impedance curve of RL, RC and RLC circuits, and match circuits to their curves.
Switching RL Circuits
Right after a switch flips in a circuit with coils: the inductor current cannot jump.
Torque
Lever arms and torques: levers and tools, beams on supports, ladders, tipping over, and centres of mass.
Coulomb Force
Point charges: Coulomb’s law, factors, and net forces as vectors, from charges in a line to rankings and points of zero force.
Energy Conservation
Falls, throws, pendulums and springs: from energy in each state to speeds and heights, with numbers or formulas.
Force Concepts
Gravity, inertia, net force and interaction: spot the misconceptions behind tempting answers.
Force Systems
Boxes, ropes, pulleys and slopes: find forces and accelerations with Newton’s second law.
Electromagnetic Induction
From a flux graph to the voltage it induces and back, a loop moving through a field, Lenz's rule: the slope counts, not the value.
Motion Graphs
Speed and direction, value tables, stroboscope pictures, slopes and areas: from position to velocity and back.
Oscillations
Harmonic or not: equations of motion, their periods and graphs, and the speed and acceleration of an oscillating body.
Cyclic Processes
Processes of an ideal gas in p(V), p(T) and V(T) diagrams: describe, draw, read and switch between them.
Wave Propagation
Crests on a rope: how they travel, how a place moves, how they add up and how they are reflected at a fixed or free end.
Magnetic Forces
Hand rules for charges and currents, forces between currents, circles and helices of charged particles, and the velocity selector.