Video Transcript
The following picture shows a
voltmeter. What is the reading on the
voltmeter to the nearest volt?
This question is asking us to look
at the image of the voltmeter shown and determine the reading shown on it. We know that it is a voltmeter
because of the capital V on the device. Recall that a voltmeter is a device
that we can use to measure the potential difference across a component in an
electrical circuit.
To answer this question, we need to
take a look at the value that the red dial is pointing to on the voltmeter. But before we think about the dial,
let’s check we understand the scale on the voltmeter. We can see that the scale has four
values on it: zero volts, 50 volts, 100 volts, and 150 volts. They’re marked with long thick
black lines. Between each of these values, there
are four smaller thick black lines, marking out five intervals.
We know that the thick black lines
are separated by 50 volts, so if we divide 50 volts by the five intervals, we see
that the smaller thick black lines represent intervals of 10 volts. There are also thin black lines
that divide these 10-volt intervals into two. If we divide 10 volts by two, we
see that the thin black lines represent intervals of five volts.
Now that we understand the
voltmeter’s scale, we can look at the position of the dial. The red dial is pointing at the
zero. This means that the reading on the
voltmeter is zero volts, which is our final answer.
