2
You visited us
2
times! Enjoying our articles?
Unlock Full Access!
Byju's Answer
Standard VIII
Chemistry
Surface Tension
A rectangular...
Question
A rectangular film of liquid is extended from
(
4
c
m
×
2
c
m
)
to
(
5
c
m
×
4
c
m
)
. If the work done is
3
×
10
−
4
J
, the value of the surface tension of the liquid is
A
8.0
N
m
−
1
No worries! We‘ve got your back. Try BYJU‘S free classes today!
B
0.250
N
m
−
1
No worries! We‘ve got your back. Try BYJU‘S free classes today!
C
0.125
N
m
−
1
Right on! Give the BNAT exam to get a 100% scholarship for BYJUS courses
D
0.2
N
m
−
1
No worries! We‘ve got your back. Try BYJU‘S free classes today!
Open in App
Solution
The correct option is
C
0.125
N
m
−
1
Initial area of the film
A
i
=
4
×
2
=
8
c
m
2
=
8
×
10
−
4
m
2
Final
area of the film
A
f
=
5
×
4
=
20
c
m
2
=
20
×
10
−
4
m
2
Thus change in area
Δ
A
=
(
20
−
8
)
×
10
−
4
=
12
×
10
−
4
m
2
Work done
W
=
3
×
10
−
4
J
Using for soap films
W
=
S
(
2
Δ
A
)
where
S
is the surface tension
∴
3
×
10
−
4
=
S
×
2
×
12
×
10
−
4
⟹
S
=
0.125
N
m
−
1
Suggest Corrections
1
Similar questions
Q.
A rectangular film of liquid is extended from
(
4
cm
×
2
cm
)
to
(
5
cm
×
4
cm
)
. If the work done is
3
×
10
−
4
J
, then value of the surface tension of the liquid is
Q.
A rectangular film of liquid is extended from
(
4
c
m
×
2
c
m
)
to
(
5
c
m
×
4
c
m
)
. If the work done is
3
×
10
−
4
J
, the value of the surface tension of the liquid is