Surface energy of a liquid - class-XI

Question 1 Multiple Choice (Single Answer)

What is the change in surface energy, when a mercury drop of radius $r$ splits up into 1000 droplets of radius $r$?

$8pr^2t$
$28pr^2t$
$16pr^2t$
$36pr^2t$

Question 2 Multiple Choice (Single Answer)

Two soap bubbles have radii in the ratio of $4:3$. What is the ratio of work done to blow these bubbles?

4:3
16:9
9:16
3:4

Question 3 Multiple Choice (Single Answer)

W is the work done, when a bubble of volume V is formed from a solution. How much work is required to be done to form a bubble of volume 2V?

$2W$
$W$
$2^{1/3}W$
$2^{2/3}W$

Question 4 Multiple Choice (Single Answer)

The surface energy of a liquid drop of radius r is proportional to:

$r^3$
$r^2$
r
$\dfrac {1}{r}$

Question 5 Multiple Choice (Single Answer)

A mercury drop of radius 1 cm is broken into 106 droplets of equal size. The work done is

$(T = 35 10^{-2} N/m)$

$1.615\times 10^{-3}J$
$4.35\times 10^{-4}J$
$1.615\times 10^{-6}J$
$4.35\times 10^{-8}J$

Question 6 Multiple Choice (Single Answer)

Surface tension of a soap solution is $1.9 10^{-2} N/m.$ Work done in blowing a bubble of 2.0cm diameter will be

$7.6 10^{-6} J$
$15.2 10^{-6} J$
$16 10^{-6} J$
$2.5 10^{-6} J$

Question 7 Multiple Choice (Single Answer)

The surface tension of a soap solution is $0.035 N/m$. the energy needed to increase the radius of the bubble from $4$ cm to $6$ cm is

$1.75\times 10^{-3} J$
$1.510^{-2} J$
$310^{-3} J$
$1.510^{-4} J$

Question 8 Multiple Choice (Single Answer)

Two drops of a liquid are merged to from a single drop. In this process-

Energy is released
Energy is absorbed
Energy remains constant
First B then A

Question 9 Multiple Choice (Single Answer)

Two soap bubbles of radii 4 cm and 3 cm respectively coalesce under isothermal conditions to form a single bubble. What is the radius of the new single bubble?

$3 cm$
$4 cm$
$5 cm$
$6 cm$

Question 10 Multiple Choice (Single Answer)

A square frame of length $L$ is immersed in soap solution and taken out. The force experienced by the square plate is

$TL$
$2TL$
$4TL$
$8TL$

Question 11 Multiple Choice (Single Answer)

A spherical water drop of radius $R$ is split up into $8$ equal droplets. If $T$ is the surface tension of water, then the work done in this process is-

$4\pi R^2T$
$8\pi R^2T$
$48\pi R^2T$
$2\pi R^2T$

Question 12 Multiple Choice (Single Answer)

A drop of oil is placed on the surface of water. Which of the following statement is correct?

It will remain on it as a sphere
It will spread as a thin layer
It will partly be as spherical droplets and partly as thin film
It will float as distorted drop on the water surface.

Question 13 Multiple Choice (Single Answer)

One thousand small water droplets of equal size combine to form a big drop. The ratio of the final surface energy to the initial surface energy is: (Surface tension of water = 70 dyne/cm)

10:1
1000:1
1:10
1:1000

Question 14 Multiple Choice (Single Answer)

Two spherical soap bubbles of a radii $r _1$ and $r _2$ in vacuum coalesce under isothermal conditions. The resulting bubble has the radius $R$ such that

$R=r _1+r _2$
$R^2 ={ r _1^2 + r _2^2}$
$R=\dfrac{r _1+r _2}{r _2}$
none of these

Question 15 Multiple Choice (Single Answer)

What is the change in surface energy, when a mercury drop of radius $R$ splits up into $1000$ droplets of radius $r$?

$8\pi R^2T$
$16\pi R^2T$
$24\pi R^2T$
$36\pi R^2T$

Question 16 Multiple Choice (Single Answer)

Potential energy of a molecule on the surface of a liquid is as compared to another molecule inside of the liquid is

More
Less
Both a and b
None of these

Surface energy of a liquid - class-XI

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