Assertion : A large force is required to draw apart normally two … - Vidyadip

MCQ

$Assertion :$ A large force is required to draw apart normally two glass plates enclosing a thin water film.
$Reason :$ Water works as glue and sticks two glass plates.

A
If both Assertion and Reason are correct and the Reason is a correct explanation of the Assertion.
B
If both Assertion and Reason are correct but Reason is not a correct explanation of the Assertion.
✓
If the Assertion is correct but Reason is incorrect.
D
If both the Assertion and Reason are incorrect.

✓

Answer

Correct option: C.

If the Assertion is correct but Reason is incorrect.

c
In this case, atmospheric pressure does not comes into it because it acts in all direction. The force which is effective in case of water between two pieces of glass is adhesive force. As, adhesive forces are considered that between two different bodies; cohesive forces are internal forces of a body, resulting from attraction between the molecules of it. The attractive force between water and glass (the glass contain silicium atoms, negatively charged and water is a polar molecule so that the positive side of water is attached and causes part of the bound) keep them firmly tovether. Due to the big surface of the glass slide, the resultant force is also big. So we have to apply a large force in order to separate two glass plates enclosed with water film.

Need a full question paper?

Generate a complete, print-ready paper with questions like this in minutes — across 16+ boards, with answer keys.

Start Generating Free

Explore more

More "M.C.Q (1 Marks)" from 9.2 , surface tension→9.2 , surface tension — all question types→Physics STD 11 Science question papers→Rajasthan Board STD 11 Science question papers→Rajasthan Board question paper generator→

Similar questions

A gas for which $\gamma = 1.5$ is suddenly compressed to $\frac{1}{4}$ th of the initial volume. Then the ratio of the final to the initial pressure is

A tuning fork of frequency $340Hz$ is vibrated just above the tube of $120 cm$ height. Water is poured slowly in the tube. What is the minimum height of water necessary for the resonance .... $cm$ (speed of sound in the air $= 340 m/sec$)

A cylindrical vessel of cross-section $A$ contains water to a height $h$ . There is a hole in the bottom of radius $'a'$ . The time in which it will be emptied is

A small block starts slipping down from a point $B$ on an inclined plane $A B,$ which is making an angle $\theta$ with the horizontal section $BC$ is smooth and the remaining section $CA$ is rough with a coefficient of friction $\mu .$ It is found that the block comes to rest as it reaches the bottom (point $A)$ of the inclined plane. If $B C=2A C$, the coefficient of friction is given by $\mu=k \tan \theta$ .The value of $k$ is

A tuning fork of frequency $392 Hz,$ resonates with $50 cm $ length of a string under tension ($T$). If length of the string is decreased by $2\%$, keeping the tension constant, the number of beats heard when the string and the tuning fork made to vibrate simultaneously is

A force $\text{F}=5\hat{\text{i}}+6\hat{\text{j}}-4\hat{\text{k}}$ acting on a body produces a displacement $\text{s}=6\hat{\text{i}}+5\hat{\text{k}}$ The work done by the force is:

The coordinates of centre of mass of a uniform flag shaped lamina (thin flat plate) of mass $4\;kg$. (The coordinates of the same are shown in figure) are

The weight of man in a lift moving upward is $608\,N$ while the weight of the same man in the lift moving downwards with the same acceleration is $368\, N$. His normal weight is ............ $ N$

A molecule moving along a straight line possess ________ degree of freedom.

An object at rest at the origin begins to move in the $+x$-direction with a uniform acceleration of $1 \,m / s ^2$ for $4 \,s$ and then it continues moving with a uniform velocity of $4 \,m / s$ in the same direction.The $x-t$ graph for object's motion will be