Physical Properties of Matter (Physics)

Total Questions: 54

51. Why it is easier to swim in the sea than in a river? [U.P. Lower Sub. (Pre) 2002]

Correct Answer: (a) The sea water is salty
Solution:

It is easier to swim in sea water than in a river because, the sea water contains salts which increase the density of water and also increase its upthrust so, the chances of sinking get reduced and one can easily swim in such water.

52. A body-weight is highest in which among the following? [U.P. P.C.S. (Mains) 2017]

Correct Answer: (c) Hydrogen
Solution:

The upthrust force or buoyant force in Hydrogen will be less than other matters because it is the lightest gas. So, option (c) is the correct answer.

53. When a ship enters a sea from a river, what happens? [U.P. Lower Sub. (Pre) 2004, U.P. P.C.S. (Pre) 1992]

Correct Answer: (a) It rises a little
Solution:

When a ship enters a sea from a river, the ship is elevated due to the higher density of salty sea water than the river.

54. Assertion (A): When a ship enters a sea from a river, it rises a little. [U.P.P.C.S. (Pre) 2003, U.P.U.D.A./L.D.A. (Pre) 2002]

Reason (R): The density of sea water is greater than that of river water.

In the context of the above statements, which of the following is true:

Correct Answer: (a) Both A and R are true and R. is the correct explanation of A.
Solution:

When a ship enters a sea from a river, the ship is elevated due to the higher density of salty sea water than the river.