KCET 2021 Physics Solved Paper

As we know, height of capillary rise or fall of a liquid in a capillary tube is given as
h=

2T‌cos‌θ

rρg

⇒ h∝

1

r

...(ii)
where, r is the radius of the capillary lube.
Given, height of water level in capillary tube P=

2

3

height of water in capillary tube Q.
⇒ hP=

2

3

hQ
or

hP

hQ

=

2

3

From Eq. (i), we can write

hp

hQ

=

rQ

rp

⇒

2

3

=

rQ

rP

or rP:rQ=3:2
As diameter of the tube is equals to twice the radius.
So,

(diameter)P

(diameter)Q

=

3

2