मराठी

There are two beautiful lakes near a village. People come for boating and picnics in both the lakes. The village Panchayat is worried that with the noise of the boats the birds will stop coming.

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प्रश्न

There are two beautiful lakes near a village. People come for boating and picnics in both the lakes. The village Panchayat is worried that with the noise of the boats the birds will stop coming. The Panchayat wants motorboats in only one lake. The other lake will be saved for the birds to make their nests.

  • What is the length of the boundary of lake B in the drawing?
एका वाक्यात उत्तर
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उत्तर

When we measure the boundary of lake B with the help of a thread, it comes out to be around 25 cm.

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पाठ 11: Area and its Boundary - Area and its Boundary [पृष्ठ १५६]

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एनसीईआरटी Mathematics Math - Magic [English] Class 5
पाठ 11 Area and its Boundary
Area and its Boundary | Q b) | पृष्ठ १५६

संबंधित प्रश्‍न

Write true or false.

Every measurement involves two things – a number and a unit.


While measuring the length of a sharpened pencil, the reading of the scale at one end is 2.0 cm and at the other end is 12.1 cm. What is the length of the pencil?


Find the answer for the following questions within the grid.

  1. 10-3 is one ______
  2. SI Unit of time is ______
  3. Cross view of reading a measurement leads to ______
  4. ______ is the one what a clock reads.
  5. ______ is the amount of substance present in an object.
  6. ______ can be taken to get the final reading of the recordings of different students for a single measurement.
  7. ______ is a fundamental quantity.
  8. ______ shows the distance covered by an automobile
  9. A tailor uses ______ to take measurements to stitch the cloth.
  10. Liquids are measured with this physical quantity.

Assertion (A): Distance between two celestial bodies is measured in terms of light year.

Reason (R): The distance travelled by the light in one year is one light year.


Numerical Problem.

Inian and Ezhilan argue about the light year. Inian tells that it is 9.46 × 1015 m and Ezhilan argues that it is 9.46 × 10 12 km. Who is right? Justify your answer.


Guess whose tail is the longest. Now measure the tails. How good is your guess?


Difference in size
Do this for yourself and find the difference.


How close was your earlier guess? Discuss.


The fencing of a square garden is 20 m in length. How long is one side of the garden?


You can play this game on the ground. Make two squares of one square meter each. Divide your class into two teams. Ready to play!

  • How many of you can stand in it?

You can play this game on the ground. Make two squares of one square meter each. Divide your class into two teams. Ready to play!

  • Which team could make more children stand in their square? How many?

There are two beautiful lakes near a village. People come for boating and picnics in both the lakes. The village Panchayat is worried that with the noise of the boats the birds will stop coming. The Panchayat wants motorboats in only one lake. The other lake will be saved for the birds to make their nests.

  • How many cm is the length of the boundary of lake A in the drawing?(use thread to find out)

There are two beautiful lakes near a village. People come for boating and picnics in both the lakes. The village Panchayat is worried that with the noise of the boats the birds will stop coming. The Panchayat wants motorboats in only one lake. The other lake will be saved for the birds to make their nests.

  • A longer boundary around the lake will help more birds to lay their eggs. So which lake should be kept for birds? Which lake should be used for boats?

There are two beautiful lakes near a village. People come for boating and picnics in both the lakes. The village Panchayat is worried that with the noise of the boats the birds will stop coming. The Panchayat wants motorboats in only one lake. The other lake will be saved for the birds to make their nests.

  • A longer boundary around the lake will help more birds to lay their eggs. So which lake should be kept for birds? Which lake should be used for boats?

Give some examples of larger length measures.


The Unit used to measure length ______.


  1. The earth-moon distance is about 60 earth radius. What will be the diameter of the earth (approximately in degrees) as seen from the moon?
  2. Moon is seen to be of (½)°diameter from the earth. What must be the relative size compared to the earth?
  3. From parallax measurement, the sun is found to be at a distance of about 400 times the earth-moon distance. Estimate the ratio of sun-earth diameters.

In an experiment to estimate the size of a molecule of oleic acid 1 mL of oleic acid is dissolved in 19 mL of alcohol. Then 1 mL of this solution is diluted to 20 mL by adding alcohol. Now 1 drop of this diluted solution is placed on water in a shallow trough. The solution spreads over the surface of water forming one molecule thick layer. Now, lycopodium powder is sprinkled evenly over the film and its diameter is measured. Knowing the volume of the drop and area of the film we can calculate the thickness of the film which will give us the size of oleic acid molecule.

Read the passage carefully and answer the following questions:

  1. Why do we dissolve oleic acid in alcohol?
  2. What is the role of lycopodium powder?
  3. What would be the volume of oleic acid in each mL of solution prepared?
  4. How will you calculate the volume of n drops of this solution of oleic acid?
  5. What will be the volume of oleic acid in one drop of this solution?

In the parallax formula D = b/θ, what must be true about the angle θ for the calculation to be correct?


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