Q1.A soap bubble has radius r and the surface tension of the soap film is T. The energy needed to double the diameter of the bubble without change of temperature is
Answer : Option DExplaination / Solution: No Explaination.
Q3.An air bubble of radius r is formed inside a tank of water of depth h. The atmospheric pressure is equal to a water column of height H. the pressure inside the bubble is
Answer : Option CExplaination / Solution: No Explaination.
Q4.It is easier to spray water to which soap is added, because
Answer : Option CExplaination / Solution:
Addition of soap decreases the surface tension of water , as we know the energy of spraying is directly proportional to the surface tension .
Q6.One thousand small water droplets of equal size combine to form a big drop. The ratio of the final surface energy to the total initial surface energy is
Answer : Option CExplaination / Solution: No Explaination.
Q7.The unit of surface tension in S.I units is given by
Answer : Option CExplaination / Solution:
surface tension is measured in force per unit length. The S.I unit is newton per meter but the CGS unit dyne per centimeter is also used.
Q9.Two match sticks are laid side by side on the surface of water. When a drop of light oil on the end of a third match stick is touched to the surface film between the two floating sticks, the two match sticks
Answer : Option DExplaination / Solution: No Explaination.