Question

What is meant by the order of magnitude of a quantity?

Answer 1

1. The order of magnitude tells us about the largeness or smallness of a physical quantity.
2. To find the order of magnitude the value of the physical quantity is expressed as a × 10^b ;where 1 ≤ a < 10 and b is a positive or a negative integer.
3. The exponent of 10, here it is b, is called of the order of magnitude.
4. To compare the physical quantities we must express them in proper units.
5. Example: Length of a football is 91 m, which can be expressed as 9.1 × 10¹ m.
6. Length of a housefly is 5 × 10^-3 m. So, the order of magnitude of football field is 1 and that of the house fly is -3.
7. The difference is 1 - (-3) = 4. Thus, we can say the length of a football field is 4 orders of magnitude larger than the length of a housefly.