Lab no 1: Capillary elevation in capillary tubes:

Part I

Location:

The location of the lab test was UDC, engineering building, C level

Objective:

The objective of the lab was to measure the capillary elevation inside the capillary tube. Following equipment were used:

• Glass capillary tubes
• Wetting agent
• Pencil and water proof card
• Methylated spirits

Following is the Procedure:

Depending on the contact between the surface of tubes, water level may rise or fall when a tube of small bore is inserted inside the water. For each tube, measure the water level. Notice the small meniscus around the tube during the water rise. The elevation is recorded and the rise is calculated with the help of the following formula:

The results are:

 ID of capillary tube mm Measured rise h(mm) Calculated rise h(mm) 0.5 22 59 0.8 18 37 1.7 15 17 2 13 15 2.2 12 13

Using the above formula i.e.

h, which is the height of the tube can be calculated by putting the values in the formula i.e.

= 0.072N/m at 25 oC

Graph

between the measured rise and the ID of capillary tube

Conclusion:

We can conclude from the above calculations that as we increase the diameter of the bore, the water rise is noticed to decrease.

PART II:

Capillary Elevation between Plates

Location:

The location of the lab test was UDC, engineering building, C level

Objective:

To find out the effect of the surface tension between flat glasses on capillary elevation.

Equipment:

• Wetting agent
• Flat glass plates
• Methylated spirits
• Pencil and water proof card

Method:

A gap is created between vertical plates and then the rise of water is observed inside it.

Procedure:

First of all water inside the gap and if needed, put cards to see the water level. The experiment is repeated with different diameters. The surface tension changes with the temperature. This is why temperature can be used to repeat the test exercise.

PART III

Archimedes’ Principle

Objective:

Verification of Archimedes principle using brass bucket and a cylinder with a lever balance and displacement vessel. The objective if this lab is to verify the Archimedes Principal with the help of brass bucket and a cylinder. Lever balance and displacement vessels are also incorporated.

Equipment:

• Lever balance
• Displacement balance
• Optional equipment

Method:

The up thrust and the displacement volumes are measured by weighing machined bucket and cylinder in the air and immersed in the water.

The following procedure is used:

The bucket and the cylinder are suspended by a fine thread. On 0-25gm balance is set to operate. The displacement vessel is filled with water and then allowed to drain to the level of spout. The cylinder is completely immersed in the displacement vessel and the displace water is alloed to collect in the container then remove the beaker. The cylinder is then removed and the mass of the bucket is noted down.

Results are presented in the following table:

 Items units results Mass of bucket only in air grams m3 = 100 Mass of water grams m4 – m3 =5.2 Gravitational force on the mass of water Newtons Mass of bucket immersed in water Grams m2 = 180 Upthrust force Newtons 0.05 Mass of bucket with cylinder in air Grams m1 = 185 Mass of bucket filled with water Grams m4 = 105.2

Conclusion:

m1 – m2 = m4-m3

185-180 = 5.2

5 = 5.2

Hence the Archimedes’ Principle is proved.