HSC Science (General) १२ वीं कक्षा - Maharashtra State Board Important Questions

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

Define surface tension and surface energy.

Prove that `g_h=g(1-"2h"/R)` where gh is the acceleration due to gravity at altitude h and h << R (R is the radius of the earth).

If the Earth completely loses its gravity, then for any body _______.

(A) both mass and weight become zero.
(B) neither mass nor weight become zero.
(C) weight becomes zero but not the mass.
(D) mass becomes zero but not the weight.

If two capillary tubes of different diameters are partially dipped in the same liquid vertically, then the rise of liquid ______.

Draw a neat labelled diagram of rise of liquid in capillary tube showing different components of tension (force).

State Kepler's laws of planetary motion.

The total free surface energy of a liquid drop is `pisqrt2` times the surface tension of the liquid. Calculate the diameter of the drop in S.l. unit.

A soap bubble of radius 12 cm is blown. Surface tension of soap solution is 30 dyne/cm. Calculate the work done in blowing the soap bubble.

In a conical pendulum, a string of length 120 cm is fixed at rigid support and carries a mass
of 150 g at its free end. If the mass is revolved in a horizontal circle of radius 0.2 m around a
vertical axis, calculate tension in the string (g = 9.8 m/s²)

A body weighs 4.0 kg-wt on the surface of the Earth. What will be its weight on the surface of a plant whose mass is `1/8` th of the mass of the Earth and radius half `(1/2)` of that of the Earth?

Show that the surface tension of a liquid is numerically equal to the surface energy per unit
area.

‘g’ is the acceleration due to gravity on the surface of the Earth and ‘R’ is the radius of the
Earth.

Show that acceleration due to gravity at height ‘h’ above the surface of the Earth is

`gh = g (R/(R+H))^2`

A big drop of radius R is formed from 1000 droplets of water. The radius of a droplet will be _______

A) 10 R

B) R/10

C) R/100

D) R/1000

State any two characteristics of the angle of contact

Calculate the work done in increasing the radius of a soap bubble in air from 1 cm to 2 cm. The surface tension of soap solution is 30 dyne/cm. (Π = 3.142).

What is the decrease in weight of a body of mass 500 kg when it is taken into a mine of depth 1000 km? (Radius of earth R = 6400 km, g = 9.8 m/s²)

When a sparingly soluble substance like alcohol is dissolved in water, surface tension of water

Define binding energy and obtain an expression for binding energy of a satellite revolving in a circular orbit round the earth.

Obtain an expression for the rise of a liquid in a capillary tube.