Question

34.Two soap bubbles of radii 1 cm and 2 cm coalesce to form a big bubble.
The radius of the big bubble is :
1 सेमी और 2 सेमी त्रिज्या के दो बुलबुले मिलकर एक बड़ा बुलबुला बनाते हैं। बड़े
बुलबुले की त्रिज्या है:​

Answer 1

Explanation:

For isothermal conditions, Boyle's law holds good.

P

1

V

1

+P

2

V

2

=PV

where

P

1

= excess pressure inside first bubble

P

2

= excess pressure inside second bubble

V

1

= volume of first bubble

V

2

= volume of second bubble

P= excess pressure of new bubble formed

V= volume of new bubble formed

P

1

V

1

+P

2

V

2

=PV

⇒

r

1

4T

×

3

4

πr

1

3

+

r

2

4T

×

3

4

πr

2

3

=

R

4T

×

3

4

πR

3

⇒R=

r

1

2

+r

2

2

=

3

2

+4

2

=5cm

Answer 2

Answer:

1.5cm

Explanation:

1cm+2cm

=3cm

because when 2 bubbles coalesce together

the size of bubble become 3cm and the radius is 1.5 cm