Advertisements
Advertisements
प्रश्न
Why do we have different units for the same physical quantity?
Advertisements
उत्तर
The value of any given physical quantity may vary over a wide range, therefore, different uns of the same physical quantity are required. e.g., The length of a pen can be easily measured in cm, the height of a tree can be measured in metres, the distance between two cities can be measured in kilometres and the distance between two heavenly bodies can be measured in light years.
APPEARS IN
संबंधित प्रश्न
How many significant figures are present in the 126,000?
How many significant figures are present in the 500.0?
Round up the following upto three significant figures:
34.216
Round up the following upto three significant figures:
0.04597
How many significant figures should be present in the answer of the following calculation?
5 × 5.364
You are given a thread and a metre scale. How will you estimate the diameter of the thread?
The mass of a box measured by a grocer’s balance is 2.300 kg. Two gold pieces of masses 20.15 g and 20.17 g are added to the box. What is
- What is the total mass of the box?
- What is the difference in the masses of the pieces to correct significant figures?
A LASER is a source of very intense, monochromatic, and unidirectional beam of light. These properties of a laser light can be exploited to measure long distances. The distance of the Moon from the Earth has been already determined very precisely using a laser as a source of light. A laser light beamed at the Moon takes 2.56 s to return after reflection at the Moon’s surface. How much is the radius of the lunar orbit around the Earth?
Just as precise measurements are necessary in science, it is equally important to be able to make rough estimates of quantities using rudimentary ideas and common observations. Think of ways by which you can estimate the following (where an estimate is difficult to obtain, try to get an upper bound on the quantity):-
the wind speed during a storm
A large ball 2 m in radius is made up of a rope of square cross-section with edge length 4 mm. Neglecting the air gaps in the ball, what is the total length of the rope to the nearest order of magnitude?
Solve the numerical example.
The diameter of a sphere is 2.14 cm. Calculate the volume of the sphere to the correct number of significant figures.
Answer the following question.
Describe what is meant by order of magnitude.
The radius of the circle is 3.12 m. Calculate the area of the circle with regard to significant figures.
How many significant figures should be present in the answer of the following calculations?
`(2.5 xx 1.25 xx 3.5)/2.01`
Using the rules for significant figures, the correct answer for the expression `(0.02858 xx 0.112)/(0.5702)` will be ______.
Significant figures in a measurement include which of the following?
Which of the following measurements contains exactly two significant figures?
The radius of Earth is written as 0.64 × 10⁷ m in scientific notation. What is its order of magnitude?
What is the least count of a measuring instrument?
