Question 12
The unit of surface tension is
a) erg cm
-2
b) N
c) dyne cm
-1
d) N m
-1
e) Both c and d
Correct Answer:
e) Both c and d
Explanation:
Surface tension is generally expressed in terms of dyne cm
-1
. In SI unit, surface tension is expressed
in terms of N m
-1
.
Question 13
Pick out the correct statement related to Boyle's law
a) When pressure increases, volume also gets increased
b) Graph of pressure Vs. volume gives straight line
c) P
1
* P
2
= V
1
* V
2
d) P a 1/V
e) None of these
Correct Answer:
d) P a 1/V
Explanation:
When pressure increases, volume gets decreased. Graph of pressure Vs volume gives curve. P
1
*
V
1
= P
2
* V
2
.
Question 14
The defect which is generally found in compounds of transition metals having variable valency
is
a) Schottky defect
b) Frenkel defect
c) Metal excess defect
d) Metal deficiency defect
e) Line defect
Correct Answer:
d) Metal deficiency defect
Explanation:
Metal deficiency defect is due to cation vacancy. Schottky defect is commonly found in ionic crystals
in which cations and anions are of similar size. Frenkel defect is shown by ionic crystals of different
size. Metal excess defect is due to anion vacancy and interstitial cation. In line defect, groups of
atoms are arranged in an irregular position.
Question 15
When a decomposition reaction involves redox reactions, it is called
