Starting Electronics

The

very

first

steps

Electronic

components

The

fact

that different resistances produce different cur-

rents if a voltage is applied

across

them, or produce

different

voltages if a current is applied

through

them,

is

one of the most useful facts in electronics.

In

electronics, an amp of current is very large — usually

we only use much smaller currents, say, a

thousandth

or

so

of an amp. Sometimes we even use currents smaller

than this, say, a millionth of an amp! Similarly, we some-

times

need only small voltages, too.

Resistances

are extremely useful in these

cases,

because

they

can be used to reduce the current flow or the volt-

age

produced