Question 8
If the speeds of sound in solid, liquid and gas are arranged in increasing order, which of the
following is a correct arrangement?
A.
Solids< liquids < gas
B.
Liquids < solids < gas
C.
Gas < liquids < solids
D.
Gas < solids < liquids
E.
Liquids < gas < solids
Correct Answer: C
Explanation:
Thespeed of sound in solids like steel and iron is 5000 m/s and 5130 m/s.The speed of sound in
liquidslike water at 0
o
C and 20
o
C is 1402 m/s and 1482 m/srespectively. The speed of sound in air
(gas)at 0
o
C and 20
o
C is 331.5 m/s and 344 m/srespectively. Thus, from the above discussion it can
be concluded that the speed of sound in solids is more than that in liquids and air.
Therefore,thecorrect arrangementfor speeds of soundis air (gas) < liquids < solids. Thus, C is the
correct answer option.
Question 9
What would be the specific gravity of a fluid having density of 944 kg/m
3
?
A.
0.967
B.
0.456
C.
0.944
D.
0.789
E.
0.45
Correct Answer: C
Explanation:
Specific gravity is a dimensionless quantity and is given as
SG = ρ
fluid
/ ρ
water
---------------- (1)
It is quite obvious from equation 1 that specific gravity is a unit less quantity. Putting the values of
densities in equation 1 we get
SG = 944 / 1000 Or SG = 0.944
Therefore, C is the correct answer option.
Question 10
A sample of gas at 313 K occupies a volume of 10 m
3
. What would be its volume at 373 K?
A.
11.92 m
3
B.
15.56 m
3
C.
10.45 m
3
