2. What is the need for standard units?
3. Write the seven fundamental S.I. units.
4. Define standard unit.
5. How many metres are there in one kilometre?
experime
C. Short Type Questions
1. How will you measure the diameter of a coin or ball? Explain with an
2. How can you calculate the measurement of an area?
3. How will you measure the following:
(a) Length of a pencil
(b) Length of a wooden block
4. Write two precautions that should be taken while measuring length with
metre scale.
5. Write the procedure for measuring the length of a curved line with the help
a divider.
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Science
Answers
the starnd unit help to undersstand in many ways
Answer:
2.Ans - We need standard unit for measurement to make our judgement more reliable and accurate. For proper dealing, measurement should be same for everybody. Thus there should be uniformity in measurement. For the sake of uniformity we need a common set of units of measurement, which are called standard units.
3.Ans - The seven SI base units, which are comprised of:
Length - meter (m)
Time - second (s)
Amount of substance - mole (mole)
Electric current - ampere (A)
Temperature - kelvin (K)
Luminous intensity - candela (cd)
Mass - kilogram (kg)
4.Ans - The second meaning of standard unit refers to a unit of particular set of units of measurement called the standard system (versus the metric system). The standard system includes the standard units of the foot, the pound (mass), and the gallon. ... United States customary units, used predominantly in the United States.
5.Ans - The kilometre (SI symbol: km; /ˈkɪləmiːtər/ or /kɪˈlɒmɪtər/), spelt kilometer in American English, is a unit of length in the metric system, equal to one thousand metres (kilo- being the SI prefix for 1000).
C. 1.Ans - we can't find the diameter of one coin then you take 10 coin and one on one and take scale and measure the coin and divide the total height into number of coins calculate you will get answer
2.Ans - To find the area of a rectangle, multiply its height by its width. For a square you only need to find the length of one of the sides (as each side is the same length) and then multiply this by itself to find the area. This is the same as saying length2 or length squared.
3.Ans -
4.Ans - To measure length with scale we should,
•Keep the ruler exactly along the length to be measured.
•Avoid using worn out portions of the ruler.
•Keep the eye vertically above the point where the measurement is to be taken.
5.Ans - Measuring Length of a Curved line
1.Tie a knot at one end of the thread.
2.Place the thread at the beginning of the line and try to measure a small initial portion of the line which is relatively straight.
3.Place your thumb at the other end of the measured portion and measure next straighter portion.
4.Repeat the above step till the end of line is reached.