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प्रश्न
Explain the need for accurate measurement and the devices to be used for that.
उत्तर
We need not be very accurate every time we take a measurement. The degree of accuracy in measurements varies according to the situations. For example,
- when someone asks about the time of the day, we do not have to be specific up to the seconds of time, because there is no need to be that accurate in the given situation. On the other hand, for laboratory purposes or for scientific experiments, we have to measure the time even up to milliseconds accurately.
- while measuring the mass of precious substances, such as gold, silver, etc., we need to be accurate in our measurement.
- in competitions and events, a difference of a second can make you lose or win the game. Thus, accurate time measurement in such cases is very important.
- shopping in our day-to-day life, like for groceries, milk, flour, etc., requires a lot of alertness on our part so that we do not get cheated. We should always check whether the measurement is done properly or not by the vendors selling these products.
The devices used for accurate measurement are:
- For time measurement, a stopwatch can be an accurate device
- For mass measurement, an electronic balance can be an accurate device.
- For length measurement, a ruler or measuring tape can be the most accurate devices.
- For temperature measurement, thermometers can be an accurate device.
संबंधित प्रश्न
Write an answer to the following question in your own words.
What precautions will you take to make accurate measurements in day-to-day affairs?
Explain, giving examples, the errors that occur while making measurements.
Give reasons.
It is not proper to measure quantities by using body parts as units.
Give reasons.
It is necessary to get the weights and measures standardized at regular intervals.
The closeness of the measured value to the original value is _______.
Explain a method to find the thickness of a hollow tea cup.
Numerical Problem.
Find the thickness of a five rupee coin with the screw gauge, if the pitch scale reading is 1 mm and its head scale coincidence is 68.
Write a note on accuracy and precision.
Match the following.
Column I | Column II |
a) Temperature | Closeness to the actual value |
b) Plane angle | Measure of hotness or coldness |
c) Solid angle | Closeness to two or more measurements |
d) Accuracy | Angle formed by the intersection of three or more planes |
e) Precision | Angle formed by the intersection of two planes |