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प्रश्न
Why is the metre length in terms of the wavelength of light considered more accurate?
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उत्तर
Metre length in terms of the wavelength of light is considered more accurate because
- The wavelength of light does not change with time, temperature, pressure, etc.
- It can be reproduced anywhere at any time because Krypton is available everywhere.
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संबंधित प्रश्न
The size of bacteria is 1 µ. Find the number of bacteria present in 1 m length.
Draw a neat and labelled diagram of a screw gauge.
Name its main parts and state their functions.
The diameter of a thin wire can be measured by
(a) A vernier scale has 10 divisions. It slides over the main scale, whose pitch is 1.0 mm. If the number of divisions on the left hand of zero of the vernier scale on the main scale is 56 and the 8th vernier scale division coincides with the main scale, calculate the length in centimetres.
(b) If the above instrument has a negative error of 0.07 cm, calculate the corrected length.
The thimble of a screw gauge has 50 divisions for one rotation. The spindle advances 1 mm when the screw is turned through two rotations.
- What is the pitch of the screw?
- What is the least count of screw gauge?
- When the screw gauge is used to measure the diameter of wire the reading on the sleeve is found to be 0.5 mm and reading on thimble is found, 27 divisions. What is the diameter of the wire in centimetres?
What is the function of ratchet in the screw gauge?
State whether the following statement is true or false by writing T/F against it.
A metre scale can measure a length of 6.346 cm.
A Vernier calliper reads a main scale reading of 2.3 cm and the 5th division of the Vernier scale coincides with a main scale division. If the least count is 0.01 cm, what is the actual reading?
