Advertisements
Advertisements
प्रश्न
Now guess the length and width of many other things. Measure and find the difference between your measure and your guess.
| Size of | Your guess in cm | Your measure in cm | ||
| Length | Width | Length | Width | |
| 100 Rupee note | ||||
| 10 Rupee note | ||||
| 20 Rupee note | ||||
| 5 Rupee note | ||||
| Post card | ||||
| Math-Magic book | ||||
Advertisements
उत्तर
| Size of | Your guess in cm | Your measure in cm | ||
| Length | Width | Length | Width | |
| 100 Rupee note | 16.2 | 7.0 | 15.5 | 7.3 |
| 10 Rupee note | 13.0 | 6.0 | 13.7 | 6.3 |
| 20 Rupee note | 15.0 | 6.5 | 14.8 | 6.3 |
| 5 Rupee note | 11.5 | 6.5 | 11.7 | 6.3 |
| Post card | 14.0 | 9.0 | 14.5 | 9.5 |
| Math-Magic book | 28.0 | 22.0 | 28.5 | 21.5 |
Difference between my guess and measurement
| Size of | Difference in cm | |
| Length | Width | |
| 100 Rupee note | 0.5 cm | 0.3 cm |
| 10 Rupee note | 0.7 cm | 0.3 cm |
| 20 Rupee note | 0.2 cm | 0.2 cm |
| 5 Rupee note | 0.5 cm | 0.2 cm |
| Post card | 0.5 cm | 0.5 cm |
| Math-Magic book | 0.5 cm | 0.5 cm |
संबंधित प्रश्न
Match the following.
| Column A | Column B |
| (1) Length | a. kilogram |
| (2) Mass | b. cubic metre |
| (3) Area | c. metre |
| (4) Volume | d. square metre |
Fill in the following chart.
| Property | Definition | Basic Unit | Instrument used for measuring |
| Length | |||
| Mass | |||
| Volume | |||
| Time |
Metre is the unit of ______.
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.

Difference in size 
Do this for yourself and find the difference.
How close was your earlier guess? Discuss.
Arbaz plans to tile his kitchen floor with green square tiles. Each side of the tile is 10 cm. His kitchen is 220 cm in length and 180 cm wide. How many tiles will he need?

Can you think of how to cut a postcard so that you can pass through it?

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.

- Find the area of lake B on the drawing in square cm. What is its actual area in square km?
Length is a fundamental quantity.
Match the following:
| Prefix | Symbol | ||
| a. | Centi | i. | k |
| b. | Nano | ii. | c |
| c. | Mili | iii. | n |
| d. | Kilo | iv. | m |
What is the unit of length?
SI unit of electric current is ______.
To measure the distance of a planet from the earth, ______ method is used.
The distance of a galaxy is of the order of 1025 m. Calculate the order of magnitude of time taken by light to reach us from the galaxy.
Consider a sunlike star at a distance of 2 parsecs. When it is seen through a telescope with 100 magnification, what should be the angular size of the star? Sun appears to be (1/2)° from the earth. Due to atmospheric fluctuations, eye can’t resolve objects smaller than 1 arc minute.
In the parallax formula D = b/θ, what must be true about the angle θ for the calculation to be correct?
The parallax method is used to measure astronomical distances because ______.
