The contact angle between a solid & a liquid is a property of ______________.

(a)

the material of solid & liquid

(b)

material of container

(c)

shape of solid

(d)

mass of solid

The properties of a surface are different from those of the bulk liquid because the surface molecules are ______________.

(a)

are smaller than other molecules

(b)

acquire charge due to collision from airmolecules

(c)

find different type of molecules in their range of influence

(d)

feel a net force in different direction

When a capillary tube is dipped into a liquid the liquid neither rises nor falls in the capillary ________.

(a)

the surface tension of liquid must be zero

(b)

contact angle must be 90^o

(c)

surface tension may be one

(d)

contact angle may be 90° (or) zero

A liquid is contained in a vertical tube of semicircular cross section the contact angel is zero. The force of surface tension on the curved part & on the flat part are in ratio ______________.

(a)

1 : 1

(b)

1 : 2

(c)

\(\pi\)  : 2 

(d)

2 : \(\pi\)

According to Kepler, planet move in _____________.

(a)

Circular orbits around the Sun

(b)

Elliptical orbits around the Sun with Sun at exact centre

(c)

Straight lines with constant velocity

(d)

Elliptical orbits around the Sun with Sun at one of its foci