The generator effect turns…
A loudspeaker and a bicycle dynamo both hold a coil and a magnet. One is fed current; the other is fed motion.
One question sorts every such machine: what goes in, and what comes out?
A loudspeaker is fed a current, and its cone moves. Current goes in; motion comes out. So the playing loudspeaker uses the motor effect.
Now the same loudspeaker is wired to a meter instead, and someone speaks into it. The sound moves the cone, and a current flows. Motion goes in; current comes out. So the loudspeaker now uses the generator effect.
An electric motor: current goes in; motion comes out. So the motor uses the motor effect.
A bicycle dynamo: the wheel spins it, and the current lights a lamp. Motion goes in; current comes out. So the dynamo uses the generator effect.
Here is the pair again: the motor effect turns current into motion; the generator effect turns motion into current.
An electric pencil sharpener: current goes in, and the blades spin. Which effect does it use?
Current goes in; motion comes out.
Current into motion is the motor effect.
The pencil sharpener uses the motor effect.
In a dance-floor tile, each footstep presses a magnet through a coil, and a current flows. Which effect does it use?
Motion goes in; current comes out.
Motion into current is the generator effect.
The tile uses the generator effect.
Here are six fast sorts. Each stem says what goes in and what comes out.
An electric guitar pickup: the steel string's wobble drives a current. Which effect does it use?
Shaking a shake flashlight slides a magnet through its coil, and current flows. Which effect does it use?
A ceiling fan: current spins the blades. Which effect does it use?
A power drill: current spins the bit. Which effect does it use?
A seismometer: the shaking ground moves its magnet, driving a current. Which effect does it use?
A phone's vibration unit: current spins a tiny off-center weight. Which effect does it use?
Which of the following machines uses the motor effect?
Asha's gadget uses the generator effect. Which of the following must be true of the gadget?
An elevator's drive runs two ways. Going up, current hauls the car. Going down, the falling car spins the drive, and current flows back out. Which statement is correct?