Chapter 5. Measurement of Length and Motion-Extra Questions Examination Based Science Curiosity Class 6 In English

Chapter 5. Measurement of Length and Motion

The following important questions are prepared according to the latest CBSE pattern and the NCERT Curiosity textbook. These questions cover all the important concepts of the chapter and help students improve their conceptual understanding and examination skills.

Important Questions with Answers

Students are advised to answer these questions on their own before referring to the solutions given below.

1 Mark Questions

Question 1. What is the SI unit of length?

Answer: The SI unit of length is the metre (m).

Question 2. Name the instrument used to measure the length of a curved object.

Answer: A measuring tape or a thread.

Question 3. What is a reference point?

Answer: A fixed object or position used to describe the location or motion of another object.

Question 4. Define motion.

Answer: Motion is the change in the position of an object with time with respect to a reference point.

Question 5. What is meant by rest?

Answer: An object is said to be at rest if its position does not change with time with respect to a reference point.

Question 6. Name the three main types of motion discussed in this chapter.

Answer: Linear motion, circular motion, and oscillatory motion.

Question 7. Which measuring instrument is used to measure the length of a table?

Answer: A metre scale.

Question 8. What is periodic motion?

Answer: Motion that repeats itself after equal intervals of time is called periodic motion.

Question 9. Why is a standard unit of measurement necessary?

Answer: It provides uniform and accurate measurements everywhere.

Question 10. What is parallax error?

Answer: It is the error caused when the scale is read from an angle instead of vertically above the marking.

2 Marks Questions

Question 1. Why were body-part measurements replaced by standard units?

Answer:

• Body parts differ from person to person.
• Measurements obtained were not accurate.
• Standard units provide uniform and reliable measurements.

Question 2. Write the relationships among kilometre, metre, centimetre, and millimetre.

Answer:

• 1 km = 1000 m
• 1 m = 100 cm
• 1 cm = 10 mm

Question 3. How can a damaged ruler still be used to measure length?

Answer:

• Start measuring from another clear marking.
• Record the initial and final readings.
• Subtract the initial reading from the final reading.

Question 4. How is the length of a curved line measured?

Answer:

• Place a thread along the curved line.
• Straighten the thread.
• Measure its length using a ruler.

Question 5. Differentiate between rest and motion.

Answer:

• An object at rest does not change its position with time.
• An object in motion changes its position with time.
• Both depend on the chosen reference point.

3 Marks Questions

Question 1. Explain the correct method of measuring the length of an object.

Answer:

• Place the ruler along the object.
• Align the zero mark with one end.
• Keep the eye vertically above the scale.
• Read the other end carefully.
• Avoid parallax error.

Question 2. Explain linear, circular, and oscillatory motion with examples.

Answer:

• Linear Motion: Motion along a straight line. Example: A train moving on a straight track.
• Circular Motion: Motion along a circular path. Example: A ceiling fan.
• Oscillatory Motion: To-and-fro motion about a fixed position. Example: A swinging pendulum.

Question 3. Why is a reference point important in describing motion?

Answer:

• It helps determine the position of an object.
• It helps decide whether an object is at rest or in motion.
• Without a reference point, motion cannot be described accurately.

Question 4. Describe the uses of different measuring instruments.

Answer:

• Ruler – Small objects.
• Metre scale – Larger objects.
• Measuring tape – Curved objects and long distances.

Question 5. Explain periodic motion with suitable examples.

Answer:

• Periodic motion repeats after equal intervals of time.
• A swinging pendulum is an example.
• The rotation of the hands of a clock is another example.
• The motion of a merry-go-round is also periodic.

Long Answer Questions

Question 1. Explain the importance of standard units of measurement.

Answer:

Standard units ensure that measurements remain the same everywhere in the world. They eliminate confusion caused by body-part measurements and provide accurate, reliable, and uniform results. Standard units are essential in science, engineering, construction, medicine, sports, trade, and everyday life. The International System of Units (SI) is accepted worldwide because it provides consistency in measurement.

Question 2. Describe the different measuring instruments and their uses.

Answer:

Different measuring instruments are used according to the size and shape of the object. A ruler is suitable for measuring small objects such as pencils and notebooks. A metre scale is used for larger objects such as tables and doors. A measuring tape is flexible and is useful for measuring curved objects, body measurements, cloth, and long distances. Choosing the correct instrument ensures accurate measurements.

Question 3. Explain the concept of rest and motion with suitable examples.

Answer:

An object is said to be at rest if its position does not change with time with respect to a reference point. If its position changes with time, it is said to be in motion. For example, a book placed on a table is at rest with respect to the table, whereas a moving bicycle is in motion with respect to the road. Rest and motion always depend on the selected reference point.

Question 4. Describe the different types of motion with examples.

Answer:

Linear motion occurs along a straight path, such as a train moving on a straight railway track. Circular motion occurs along a circular path, such as the blades of a fan or a merry-go-round. Oscillatory motion is the repeated to-and-fro movement of an object about a fixed position, such as a pendulum or a swing. Some of these motions repeat regularly and are called periodic motions.

Question 5. Explain the precautions to be taken while measuring length.

Answer:

The measuring scale should be placed exactly along the object. The zero mark must coincide with one end of the object. The eye should be positioned vertically above the reading to avoid parallax error. If the zero mark is damaged, another clear marking should be used, and the initial reading should be subtracted from the final reading. Proper measuring instruments should always be selected according to the object being measured.