List of top Physics Questions on Surface Tension asked in MHT CET

A capillary tube of radius \( r \) is dipped in water; find the height \( h \) to which water rises if the surface tension is \( T \).

A spherical air bubble is formed inside a liquid (like water). The radius of the bubble is 0.5 mm, and the surface tension of the liquid is 0.072 N/m. What is the pressure inside the bubble relative to the outside pressure?

A U tube with limbs of diameters 5 mm and 2 mm contains water of surface tension \( 7 \times 10^{-2} \, \text{N/m} \), angle of contact is zero and density \( 10^3 \, \text{kg/m}^3 \). The difference in the level in the two limbs is \( (g = 10 \, \text{m/s}^2) \)

Let \( R_1 \) and \( R_2 \) are radii of two mercury drops. A big mercury drop is formed from them under isothermal conditions. The radius of the resultant drop is

One thousand small water drops of equal radii combine to form a big drop. The ratio of final surface energy to the total initial surface energy is

An electron in the ground state of hydrogen atom is revolving in a circular orbit of radius \(R\). The orbital magnetic moment of the electron is (\(m\) = mass of electron, \(h\) = Planck’s constant, \(e\) = electronic charge)

Soap solution is used for cleaning dirty clothes because

When a capillary is dipped vertically in water, rise of water in capillary is \( h \). The angle of contact is zero. Now the tube is depressed so that its length above the water surface is \( h/2 \). The new apparent angle of contact is

Let \( R_1 \) and \( R_2 \) be radii of two mercury drops. A big mercury drop is formed from them under isothermal conditions. The radius of the resultant drop is

A body performs S.H.M. due to force \(F_1\) with time period \(0.8\,\text{s}\). If the force is changed to \(F_2\), it executes S.H.M. with time period \(0.6\,\text{s}\). Now both the forces act simultaneously in the same direction on the same body. The new periodic time is

A small mass \(m\) is suspended at the end of a wire of negligible mass, length \(L\) and cross-sectional area \(A\). The frequency of oscillation for S.H.M. along the vertical line is \([Y =\) Young’s modulus of the material of the wire\(]\)

The excess pressure inside a soap bubble of volume \( V \) is three times the excess pressure inside a second soap bubble of volume \( V_1 \). The value of \( \left( \frac{V}{V_1} \right) \) is:

A large number of liquid drops each of radius \( r \) coalesce to form a big drop of radius \( R \). The energy released in the process is converted into kinetic energy of the big drop. The speed of the big drop is: (T = surface tension of liquid, \( \rho = \) density of liquid)

The upward force of 10\(^5\) dyne due to surface tension is balanced by the force due to the weight of the water column and \( h \) is the height of water in the capillary. The inner circumference of the capillary is (Surface tension of water = \( 7 \times 10^{-2} \) N/m)

Under isothermal conditions, two soap bubbles of radii $r_1$ and $r_2$ coalesce to form a big drop. The radius of the big drop is

When a mercury drop of radius $R$ breaks into $n$ droplets of equal size, the radius $r$ of each droplet is

A wire of length 10 cm is gently placed horizontally on the surface of water having surface tension of \( 75 \times 10^{-3} \, \text{N/m} \). What force is required to just pull up the wire from the water surface?

Two small drops of mercury each of radius \( R \) coalesce to form a large single drop. The ratio of the total surface energies before and after the change is

Two small drops of liquid of same radius coalesce to form a big drop. The ratio of the total surface energies after and before the change is

The excess pressure inside a spherical drop of water is three times that of another drop of water. The ratio of their surface area is

Water rises to a height of \(15\,\text{mm}\) in a capillary tube having cross-sectional area \(A\). If the cross-sectional area of the tube is made \( \dfrac{A}{3} \), then the water will rise to a height