Question

On joining the points if we get a straight line, that graph is called.
a) Bar graph
b) Pie chart
c) Line graph
d) None of these

Answer 1

Hint:
Bar graph - Bar graphs are used to compare things between different groups or to track changes over time
Pie chart - A Pie Chart is a special chart that uses pie slices to show relative sizes of data.
Line graph - Line graphs are used to track changes over short and long periods of time.

Complete step by step solution:
A bar graph is a chart that uses bars to show comparisons between categories of data. The bars can be either horizontal or vertical. Bar graphs with vertical bars are sometimes called vertical bar graphs. A bar graph will have two axes. One axis will describe the types of categories being compared, and the other will have numerical values that represent the values of the data. It does not matter which axis is which, but it will determine what bar graph is shown. If the descriptions are on the horizontal axis, the bars will be oriented vertically, and if the values are along the horizontal axis, the bars will be oriented horizontally.
A Pie Chart is a type of graph that displays data in a circular graph. The pieces of the graph are proportional to the fraction of the whole in each category. In other words, each slice of the pie is relative to the size of that category in the group as a whole. The entire “pie” represents 100 percent of a whole, while the pie “slices” represent portions of the whole.
A line graph is a type of chart used to show information that changes over time. We plot line graphs using several points connected by straight lines. We also call it a line chart. The line graph comprises two axes known as the ‘x’ axis and the ‘y’ axis. A chart which displays information as a series of data points connected by a straight line is known as a line graph.

So, Option c is correct.

Note:
There are many different types of bar graphs. They are not always interchangeable. Each type will work best with a different type of comparison. The comparison you want to make will help determine which type of bar graph to use. First we'll discuss some simple bar graphs.
A simple vertical bar graph is best when you have to compare between two or more independent variables. Each variable will relate to a fixed value. The values are positive and therefore, can be fixed to the horizontal value.
Pie charts give you a snapshot of how a group is broken down into smaller pieces. The following chart shows what New Yorkers throw in their trash cans. You could read that New Yorkers (perhaps surprisingly) throw a lot of recyclables into their trash, but a pie graph gives a clear picture of the large percentage of recyclables that find their way into the trash.
Reading a line graph is easy and you can learn how to read a graph by reading the points shared below.
First, take a look at the two axes and try to understand what these axes denote.
Then look at the graph and examine the values of the points situated in the lines of the graph.
Follow the lines and figure out if there is any kind of rise or fall. Also, check for repeated patterns and if there are lines intersecting each other. This way, you will get to know the purpose of the line graph.
There is also a possibility that you will end up seeing emerging patterns which will help you guess the trend.