Direction: Read the following text. Choose
the best word or phrase for each numbered blank.
If you were 1 , and took a cup
to the kitchen sink, you might first turn the tap 2
just a little way, so that only a thin
3 of water came from it. Then you would turn the tap a bit
4 . Not only would there be more water,
but also it would come out with greater force. If you
5 it on as far as it would go, you would get no water in
your cup at all, 6 it would come from
the tap in so powerful a jet 7 it would
bounce straight out of the cup again, and most likely drench you.
In that stream of water, then, are three things—or rather, two things and
8 result. Firstly, the amount or
quantity, or current of water. Secondly, the pressure
9 it. And thirdly, the power of the jet, which is the
result, or 10 of the current of water
and the force pushing it. ELECTRICAL
POWER 11 this
is not quite the same as in electricity, it helps 12
understanding amps, volts and watts. For the volt is the
13 of electrical pressure, or force.
The amp (short for ampere) is the unit of electrical current, 14 the watt is the unit of electrical
power. A watt is the power 15
by an ampere of current 16 in a circuit at a pressure of one volt. So the more the volts and amps there
are, the more watts. 17 in that water
tap, the more current there is, and the more pressure, then the greater the
resulting power. The word "pressure" is not
18 correct, however, when used about volts. They are better
19 as units of force—scientists and
engineers 20 them units of
"electromotive force", or E.M.F.