Electroscope
ð Charging by conduction
Allow a positively charged object close to touch a neutral object. Free electrons in the neutral attracted to the positive object and pass over to it - becoming + charged - two
objects end up having same charged
ð Induced charge
Same as above except the two object are close but do not touch. Free electrons to not move to end near positive object but do not cross over - leaving a positive charge at
the opposite end.
ð Ground
Zero reference point against which all voltages (electrical pressure) are measured. There are 2 types: electrical and earth
ð Electroscope
A device that can be used to detect electric charge (see below for expanded description and photo)
ð Electrometer
An electrical instrument for measuring electric charge or electrical potential difference. There are many different types, ranging from historical hand-made mechanical
instruments to high-precision electronic devices. The simpler but related instrument, the electroscope, works on similar principles but only indicates the relative magnitudes
of voltages or charges.
An instrument for detecting the presenfce of static electricity
Consists of two thin metal leaves suspended from a metal hook
When the hook is brought near a source of static electricity, some of the electrons in the hook are pushed to the leaves (if the source is negative) or pulled up to the hook from the
leaves if the source is positive
Either way, the leaves are now charged the same way as each other and so they repel each other.
The amount they open up is proportional to the charge of the source - if the sources are always held the same distance from the hook
