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1. Explain thermal expansion with suitable examples.
The on is called the thermal expansion of that substance.
Uses of thermal expansion:
(i) Fitting the iron rim on the wooden wheel:
The iron ring is always made in diameter than that of the wooden wheel. Therefore, the iron ring slip onto the rim of the wooden wheel.
Now the iron ring is heated to a higher temperature, it results in the in the size of the ring, and the hot ring is then easily slipped onto the wooden wheel's rim. Coldwater is poured on the iron ring to in size and hold the wooden wheel tightly.
(ii) Riveting:
Riveting is one of the most cost-effective and superior methods of fastening (join two parts). Rivets have a head on one side, a tail on the other used to join two steel plates together.
For using the rivets, they are till they become hot red and are then they are placed in the hole.
They are heated so that they become and . Then they are pressed from one side, and ahead at the other end is formed. When the hot rivet is fixed, and it the plates together. When cooled, the rivet will and keep the two plates tightly together.
(iii) Gaps are left in between the rails while laying a railway track:
An increase in temperature during the summer days causes . So, in order to permit at the joints of the rails, a is provided in between the rails while fixing a railway track.
If such a gap is not left at the rail's joints, the track will . It will cause derailment of trains.
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