Question

C Numerical Problems
1. Atomic radius of a certain atom is 1.2 Å. Express it in
metres. Also, determine its volume.
2. Half-life period of a certain radioactive sample is
138 days. Express it in seconds.
3. Express a joule, the SI unit of energy, in terms of
fundamental units.
4. A car is running with a speed of 117 kilometres per
hour. Calculate the magnitude of speed in SI units.
5 Light from a star reaches the earth in 8.7 years. Find the
distance of the star from the earth in metres. Given that
1 light year = 9.46 x 1015
m.
6. The main scale of a vernier is graduated in millimetres.
The sliding scale has 25 divisions. Find the least count
of vernier.
7. A screw gauge has a pitch 1 mm and there are
100 divisions on the circular scale. While measuring the
thickness of a thin mica sheet, the main scale reading
is zero and 43rd division of circular scale is coinciding
with the reference line. Determine the least count of the
screw gauge and the thickness of mica sheet.
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Answer 1

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