Question 3 :
Two spheres of the same material, but of radii R and 3R are allowed to fall vertically downwards through a liquid of density $\sigma$. The ratio of their terminal velocities is

Question 5 :
The surface energy of liquid film on a ring of area $0.15 m^{2}$ is (Surface tension of liquid $5Nm^{-1}$)<br>

Question 7 :
Assertion: Falling raindrops acquire a terminal velocity. Reason: A constant force in the direction of motion and a velocity dependent force opposite to the direction of motion, never results in the acquisition of terminal velocity.

Question 9 :
Assertion : Falling raindrops acquire a terminal velocity.<br>Reason : A constant force in the direction of motion and a velocity dependent force opposite to the direction of motion, always result in the acquisition of terminal velocity.

Question 10 :
The velocity of a ball of mass m density d1d1 becomes constant after some time.The viscous force acting on the ball will be:

Question 12 :
Assertion: Two bodies at different temperatures, if brought in thermal contact do not necessary settle to the mean temperature. Reason: The two bodies may have different thermal capacities.

Question 17 :
When a substance changes from one state to another, it absorbs or loses a large amount of heat without any change in temperature. What does this type of energy known as?<br>

Question 18 :
In a process 10 g of ice at $-5^oC$ is converted into the steam at $100^oC$.&#160;If specific heat of ice is $0.5 \ cal g^{-1} {\;}^oC^{-1}$, then the amount of heat required to convert 10 g of ice from $-5^oC$ to $0^oC$ is :

Question 19 :
A $50 g$ cube of ice and $500 g$ of boiling water are mixed in an open container. Which of the following is most likely to occur?<br/>

Question 20 :
There is a mixture of three solid compounds A, B and C. Out&#160;of these compounds A and C are soluble in water and&#160;compound C is sublimable also. In what sequence the&#160;following techniques can be used for their effective separation?<br/>I. Filtration<br/>II. Sublimation<br/>III. Crystallisation from water extract<br/>IV. Dissolution in water