Question

Match the following columns .

Column 1	Column 2
Plimsoll line	Submarine
Based on same principle as the fish	Iceberg
Fish	Ship
Titanic	Buoyancy tank
Submarine	Air sac

Answer 1

Part A:

1. Plimsoll line is a reference mark located on the ship's hull.
2. It is to indicate the maximum depth to which the vessel may be safely immersed when loaded with cargo.

Thus, A - III.

Part B:

1. The submarine works on a principle similar to that of the fish.
2. It is a kind of ship with variable and controllable mass and can be made to float or submerge in water as desired.

Thus, B - I.

Part C:

1. Fishes can come up or go deep into the water at will.
2. This is because nature has provided an air sac inside the body of the fish which it can inflate or deflate at will.
3. When it inflates the air sac, its volume increases, and hence the upthrust on it increases and it is pushed up.

Thus, C - V.

Part D :

1. Large masses of ice sometimes float on the surface of the sea called icebergs.
2. The unseen or unobserved volume of icebergs poses a serious threat to any ship that may collide with the icebergs.
3. Luxury ship “Titanic” sank into the sea after colliding with an iceberg on its maiden voyage.
4. A large number of people lost their lives in this accident in the sea.

Thus D - II.

Part E:

1. Submarine works on a principle similar to that of fish.
2. It has a watertight, closed steel vessel designed to displace water more than its weight and hence floats over the sea.
3. In its hull there are large tanks known as buoyancy tanks.
4. It helps when this submarine is submerged.

Thus E - IV.

Hence, A-III, B - I, C - V, D - II, E - IV.