NCERT Class 6 Science Chapter 5
Measurement of Length and Motion
This chapter guides Class 6 CBSE students through the concepts of measurement, with a focus on length and different types of motion. Students learn the importance of standard units in the SI system, how to correctly use a ruler, and the concept of least count. The chapter also categorizes different types of motion such as rectilinear, circular, and oscillatory motion with real-life examples.
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Key Terms
- Measurement
- The process of comparing an unknown quantity with a known standard quantity to determine its value.
- SI Unit
- The International System of Units — the globally accepted standard for measurement; the SI unit of length is the metre (m).
- Least Count
- The smallest measurement that can be accurately read from a measuring instrument.
- Rectilinear Motion
- Motion along a straight line, such as a car moving on a straight road.
- Circular Motion
- Motion along a circular path, such as the blades of a fan or a stone tied to a string being whirled.
- Oscillatory Motion
- A to-and-fro or back-and-forth motion about a central position, such as the swinging of a pendulum.
Frequently Asked Questions
What is the SI unit of length in Class 6 Science?▾
The SI unit of length is the metre (m). Other commonly used units include kilometre (km) for large distances and centimetre (cm) or millimetre (mm) for smaller measurements.
What are the types of motion in Class 6 Science Chapter 5?▾
The three main types of motion covered in Class 6 are: rectilinear motion (in a straight line), circular motion (along a circular path), and oscillatory motion (back and forth). Some objects can show more than one type of motion simultaneously.
What is least count in Class 6 measurement?▾
Least count is the smallest value that can be measured by a given instrument. For a standard ruler, the least count is usually 1 mm (0.1 cm), meaning it cannot measure distances smaller than 1 mm accurately.
Why do we need standard units of measurement in Class 6?▾
Standard units ensure that measurements are consistent and understood universally. Without standard units, the same quantity could be described differently by different people, causing confusion in science, trade, and engineering.
What is the difference between distance and length in Class 6 Science?▾
Length refers to the measurement of an object from one end to another, while distance refers to the total path covered between two points. Both are measured using the same units (metre, centimetre, etc.).
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