NEET UG Physics Properties of Liquid of Solid MCQs with answers available in Pdf for free download. The MCQ Questions for NEET Physics with answers have been prepared as per the latest NEET Physics syllabus, books and examination pattern. Multiple Choice Questions form important part of competitive exams and NEET exam and if practiced properly can help you to get higher rank. Refer to more topic wise NEET Physics Questions and also download more latest study material for all subjects and do free NEET Physics Mock Test
Properties of Liquid of Solid NEET Physics MCQ
NEET Physics students should refer to the following multiple-choice questions with answers for Properties of Liquid of Solid in NEET. These MCQ questions with answers for NEET Physics will come in exams and help you to score good marks
Properties of Liquid of Solid MCQ Questions with Answers
Surface tension of a liquid is measured by the force acting per unit length on either side of an imaginary line drawn on the free surface of liquid, the direction of this force being perpendicular to the line and tangential to the free surface of liquid. So if F is the force acting on one side of imaginary line of length l. then T = Fl.
1. It depends only on the nature of liquid and is independent of the area of surface or length of line considered.
2. It is a scalar as it has a unique direction which is not to be specified.
3. Dimension M1 L T-2
4. Unit : N/m (SI)
5. It is a molecular phenomenon and its root cause is the electromagnetic forces.
Force Due to Surface Tension
If a body of weight W is placed on the liquid surface, whose surface tension is T, and if F is the minimum force required to pull it away from the water then value of F for different bodies can be calculated by the following table.
Examples of Surface Tension :
1. When mercury is split on a clean glass plate, it forms globules. Tiny globules are spherical on the account of surface tension because force of gravity is negligible. The bigger globules because force of gravity is negligible. The bigger globules get plattened from the middle but have round shape near the edges.
2. When a molten metal is poured into water from a suitable height, the falling stream of metal breaks up and the detached portion of the liquid in small quantity acquire the spherical shape.
3. Rain drops are spherical in shape because each drop tends to acquire minimum surface area due to surface tension, and for a given volume, the surface area of sphere is minimum.
4. Oil drop spreads on cold water. Whereas it may remain as a drop on hot water. This is due to the fact that the surface tension of oil is less than that of cold water and is more than that of hot water.
5. If a small irregular piece of camphor is floated on the surface of pure water, it does not remain steady but dances about on the surface. This is because, irregular shaped camphor dissolves unequally and decreases the surface tension of the water locally. The unbalanced forces make it to move haphazardly
in different directions.
6. Take a frame of wire and dip it in soap solution and take it out, a soap film will be formed in the frame. Place a loop of wet thread gently on the film. It will remain in the form, we place it on the film according to figure.
Now, piercing the film with a pin at any point inside the loop, It immediately takes the circular from as shown in figure.
7. When a greased iron needle is placed genetly on the surface of water at rest, so that it does not prick the water surface, the needle floats on the surface of water despite it being heavier because the weight of needle is balanced by the vertical components of the forces of surface tension. If the water surface is pricked by one end of the needle, the needle sinks down.
8. Hair of shaving brush / painting brush when dipped in water spread out, but as soon as it is taken out, its hair stick together.
Factors affecting surface tension
1. Temperature :
The surface tension of liquid decreases with rise of temperature. The surface tension of liquid is zero at its boiling point and it vanishes at critical temperature. At critical temperature, intermolecular forces for liquid and gases becomes equal and liquid can expand without any restriction. For small temperature differences, the variation in surface tenstion with temperature is linear and is given by the relation.
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