First slide

Surface tension

Question

A disc of paper of radius R has a hole of radius r. It is floating on a liquid of surface tension T. The force of surface tension of the disc is

Easy

A

T x 2πR
B

T x 2π(R - r)
C

T x 2π(R + r)
D

T x 4π(R + r)

Solution

Since water has single free surface total length of boundary = (2πR + 2πr)
Magnitude of total surface tension force = (2πR + 2πr) x T ⇒ 2π(R + r)T

Get Instant Solutions

When in doubt download our app. Now available Google Play Store- Doubts App

Recieve an sms with download link

Doubts App

OR

SCAN ME

Doubts App

Doubts App