Electricity
An electroscope is charged positively as indicated by foil leaves that stand apart. As a negative charge is brought close to the electroscope, the leaves become this
closer together
Refrigerator magnets are typically this
short range
The pendulum with the greatest frequency is one with the
shortest length
The amplitude of a sound is most closely related to this
its' loudness
Hot roads will often produce this phenomenon
mirage
A proton and an electron are placed in an electric field. This undergoes the greater acceleration.
electron
Magnetic field lines about a current-carrying wire circles this wire in this way
closed loops
If you double the frequency of a vibrating object, its period does this
halves
Just as a sustained flow of water in a hydraulic circuit needs a pump, in electric circuits the flow of charge needs
voltage
Snow would appear yellow if this happened to Earth's atmosphere
it became thicker
A main difference between gravitational and electric forces is that electrical forces
repel or attract.
If you drop a bar magnet in a vertical copper pipe it will fall slowly because it has this that resists the motion of the magnet
magnetic field
The frequencies of sound that carry farther in air are
low
If a plane is not streamline, flies low and is large its' sonic booms will be
louder
In a converging lens, objects infinitely far away are focused here
at the focal point
Lillian safely touches a 100,000-volt Van de Graaff generator. Although the voltage is high, the relatively small amount of charge means a relatively small amount of
Energy transfer
The primary of a transformer is the coil connected to this
the input power line
To say that one wave is out of phase with another is to say that the waves are this
Out of step
In choosing between sound waves and radio waves, this has the less speed
sound waves
A pinhole cameras has no lens. The tiny pinhole opening insures that rays of light from different parts of an object do not do this
overlap
Imagine a single charge q placed at one corner of a square, and that the electric field at the center of the square is F/q. If two other equal charges are placed at the adjacent corners of the square (leaving the opposite corner "blank"), the electric field at the center of the square is this
F/q
Induced electric and magnetic fields result in
electromagnetic waves
The speed of sound depends on this
the medium in which it travels
this is between 15 and 25 decibels
threshold of hearing
Stare at a red wall for a few minutes and then gaze at a white wall. Due to retina fatigue you see this color
cyan
The amount of current in a CFL rated 75W 140V is about
0.5 Amps
Radio broadcast, mobile phones and household electricity are all examples of this
the transmission of power from one place to another
A radio wave is this type of wave
transverse
Wave interference in musical sounds creates this phenomena
beats
A person standing waist-deep in a swimming pool appears to have short legs because of this light phenomena
refraction