Answer very briefly.
1. Define measurement.
| Image Video News |
2. Define standard unit.
It is
defined as a specific magnitude of a physical
quantity that has been adopted by law or
convention
| Image Video News |
3. What is the full form of SI system?
International
System of Units
| Image Video News |
4. Define least count of any device.
| Image Video News |
5. What do you know about pitch of screw gauge?
The pitch of the screw
is the distance moved by
the tip of the screw for one
complete rotation of the head.
It is equal to 1 mm in typical screw gauges.
| Image Video News |
6. Can you find the diameter of a thin wire of length 2 m using the ruler from your instrument box?
2. The diameter of a thin wire can be measured using a screw gauge
| Image Video News |
Answer briefly
1. Write the rules that are followed in writing the symbols of units in SI system.
1. Small letters are used as symbols for units not derived from a proper noun.
Eg: m for metre
2. The symbols of the units are not expressed in plural form.
Eg: 10 kg not as 10 kgs
| Image Video News |
2. Write the need of a standard unit.
1. In earlier time, different unit systems were used by people from different countries.
2. At the end of the Second World War there was a necessity to use worldwide system of measurement.
3. Hence, Sl system of Units was developed and recommended by General Conference on Weights and Measures at Paris in 1960 for International usage.
| Image Video News |
3. Differentiate mass and weight.
| Mass | Weight |
| It is a fundamental quantity | It is a derived quantity |
| It has magnitude alone - scalar quantity | It has magnitude and direction - vector quantity |
| Remains the same everywhere. | Varies from place to place. |
| Its unit is kilogram (kg) | Its unit is newton (N). |
| Image Video News |
4. How will you measure the least count of
vernier caliper?
1. The smallest length which can be measured by a vernier caliper is called its least count.
2. Least count
| Image Video News |
Answer in detail
1. Explain a method to find the thickness of a hollow tea cup.
1. The thickness of a hollow tea cup can be determined using a screw gauge
2. How will you find the thickness of a one
rupee coin?
2. Determine the pitch, the least count and the zero error of the screw gauge
3. Place the tea cup between the measuring faces
4. Rotate the head until the cup is held firmly with the help of ratchat
5. Note the PSR and HSR value
6. The thickness of the cup is given by PSR+CHSR( corrected HSR)
7. Repeat the experiment for different positions of the cup
8. Tabulate the readings
9. Take the average value to minimise error
| Image Video News |
1. The thickness of a one rupee coin can be determined using a screw gauge
2. Determine the pitch, the least count and the zero error of the screw gauge
3. Place the coin between the measuring faces
4. Rotate the head until the coin is held firmly with the help of ratchat
5. Note the PSR and HSR value
6. The thickness of the cup is given by PSR+CHSR( corrected HSR)
7. Repeat the experiment for different positions of the coin
8. Tabulate the readings
9. Take the average value to minimise error
| Image Video News |