Concept of Force

Q. When a liquid is taken in a capillary tube, flat meniscus is observed. Choose the correct option.

1. Angle of contact is ${90}^{\circ }$
2. Cohesive forces between liquid molecules is greater than the adhesive forces between liquid molecules and glass
3. Cohesive forces between liquid molecules is less than the adhesive forces between liquid molecules and glass.
4. None of these

Q. If $F$ represents the strength of cohesive force, then what will be the correct order for strength of cohesive force for solid, liquid and gas ?

1. $F_{solid}<F_{liquid}<F_{gas}$
2. $F_{solid}>F_{liquid}>F_{gas}$
3. $F_{solid}<F_{liquid}=F_{gas}$
4. $F_{liquid}>F_{gas}>F_{solid}$

Q. A concave meniscus is observed for a liquid kept in a capillary tube, then angle of contact can be

1. ${85}^{\circ }$
2. ${93}^{\circ }$
3. ${100}^{\circ }$
4. ${95}^{\circ }$

Q. A cylindrical wire of length $0.1\text{m}$ has specific gravity $11$. What is the maximum diameter of the wire that can float on the surface of water, if surface tension of water is $0.07\text{N/m}$. (Take $g=10{\text{m/s}}^2$)

1. $0.7\text{mm}$
2. $\frac{0.7}{11}\text{mm}$
3. $\frac{14}{11}\text{mm}$
4. $\frac{0.8}{3}\text{mm}$

Q. When a liquid is taken in a capillary tube, flat meniscus is observed. Choose the correct option.

1. Angle of contact is ${90}^{\circ }$
2. Cohesive forces between liquid molecules is greater than the adhesive forces between liquid molecules and glass
3. Cohesive forces between liquid molecules is less than the adhesive forces between liquid molecules and glass.
4. None of these