Class 8 Linear Graphs — practice questions with answers
Coordinate Geometry · 5 sample questions from the school syllabus. Try each one, then open the answer and the worked solution.
1. What do we call a graph in which all the plotted points lie on one straight line?
- AA bar graph
- BA linear graph
- CA pie chart
- DA histogram
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Answer: B) A linear graph
When the points of a graph lie on a single straight line, it is called a linear graph.
2. Where does the graph of y=6x meet the axes?
- AAt (0, 6)
- BAt (6, 0)
- CIt does not meet them
- DOnly at the origin
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Answer: D) Only at the origin
When x=0, y=0. So the line passes through (0, 0) and meets both axes only there.
3. Ravi cycles at a steady speed. Use his distance–time graph to find his speed.
- A60 km/h
- B15 km/h
- C10 km/h
- D4 km/h
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Answer: B) 15 km/h
He covers 60 km in 4 hours. Speed = 60 ÷ 4 = 15 km/h.
4. If the points of a graph lie on a straight line through the origin, how are the two quantities related?
- AThey are in inverse proportion
- BThey are not related
- CThey are always equal
- DThey are in direct proportion
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Answer: D) They are in direct proportion
A straight line through the origin means y=kx: y is a fixed multiple of x, i.e. direct proportion.
5. Geeta starts her walk 2 km from home and walks away at a steady speed, as the graph shows. What is her speed?
- A4.7 km/h
- B12 km/h
- C2 km/h
- D4 km/h
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Answer: D) 4 km/h
Distance covered = 14 − 2 = 12 km in 3 hours. Speed = 12 ÷ 3 = 4 km/h. (14 ÷ 3 ≈ 4.7 forgets her 2 km start.)