Question

If the surface tension of a liquid is T, the gain in surface energy for an increase in liquid surface by A is

• A. $A T ^ { - 1 }$
• B. $A T$
• C. $A ^ { 2 } T$
• D. $A ^ { 2 } T ^ { 2 }$

Answer 1

Answer: (D)

$A ^ { 2 } T ^ { 2 }$

Answer 2

$W = 8 \pi R ^ { 2 } T = 8 \times \pi \times \left( 10 ^ { - 2 } \right) ^ { 2 } \times 2 \times 10 ^ { - 2 }$