physical properties of materials - Category wise Question and Answer Practice Test with Solutions

Question : 41 [UPPCS (Mains) 2015]

The maximum density of water is at

a) 277 Kelvin

b) 273 Kelvin

c) 373 Kelvin

d) 269 Kelvin

Question : 42

The load verses elongation graph for four wires is shown. The thinnest wire is

a) b

b) a

c) c

d) d

Question : 43 [IAS (Pre) 2011]

The surface of a lake is frozen in severe winter, but the water at its bottom is still liquid. Why? Following are some options

a) Since, the surface of the lake is at the same temperature as the air, no heat is lost

b) The density of water is maximum at 4°C

c) Ice is a bad conductor of heat

d) None of the above

Question : 44 [UPPCS (Pre) 2003]

Assertion (A):
When a ship enters a sea from a river, it rises a little.
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?

a) Both (A) and (R) are true, but (R) is not the correct explanation of (A)

b) (A) is true, but (R) is false

c) Both (A) and (R) are true and (R) is the correct explanation of (A)

d) (A) is false, but (R) is true