Physics Learn: April 2025

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Study of Osmosis by Potato Osmometer, Biology practical std 11 & 12

Study of Osmosis by Potato Osmometer,

Potato Osmosis practical

Study of Osmosis by Potato Osmometer

AIM :- To study osmosis by potato osmometer.

INSTRUMENTS AND MATERIALS Petridish, scalpel, pins, Potatoes, sugar, water, eosine (stain).

Conclusion :-

(A) When Potato bath is placed in Hypotonic solution due to osmosis the water flows from petridish containing hypotonic solution to the hypertonic solution in the potato bath and water level increases.

(B) When potato bath is placed in hypertonic solution due to osmosis the water flows from potato bath containing hypotonic solution to the hypertonic solution in petridish and water level decreases.

Center punch for ITI fitter, Mechanic with animated video

Center Punch ITI Fitter

Center punch for ITI fitter, mechanic with animated video.

Center punch for ITI fitter mechanical work.

It is made up of High Carbon Steel.

Center punch

Pointer angle 90 degree.

Center punch

Grind Center Punch.

Center punch use

Hold punch perpendicular to work piece

Center punch use and hammer stroke position

Work piece on which punching is done

Hammer Stroke should be straight to the head of the punch.

Center punch use and hammer stroke position

You will get deep impression which is on punch shape in metal

Cross section of punch impression.

Center punch impression on metal

Cross section Center punch impression on metal

More details view video
Grinding process of Center Punch practical with video.

To prepare ammonia gas in the laboratory and study its properties GSEB std 8 to 12

Prepare Ammonia Gas

To prepare ammonia gas in the laboratory

AIM : To prepare ammonia gas in the laboratory and study its properties

THEORY : On heating a mixture of ammonium chloride and calcium hydroxide, we get ammonium gas.

APPARATUS : Big hard glass tube, delivery tube, hollow glass tube, Bunsen burner, glass rod, two single-holed rubber cork, four to five gas jar with lids, stand and one CaO bottle as shown in the figure.

CHEMICALS : Calcium hydroxide, ammonium chloride, concentrated hydrochloric acid, red and blue litmus papers.

Preparation of Ammonia gas

Prepare Ammonia Gas In Laboratory (step-1)

Prepare Ammonia Gas In Laboratory (step-2)

Prepare Ammonia Gas In Laboratory (step-3)

Prepare Ammonia Gas In Laboratory (step-4)

Prepare Ammonia Gas In Laboratory (step-5)

Prepare Ammonia Gas In Laboratory (step-6)

Observation :

i. Colour of ammonia gas :

ii. Odour or smell of ammonia gas :

iii. Ammonia gas is collected by downhard displacement of air therefore it is than air.

iv. Use moist red and blue litmus papers and check the effect on ammonia gas and conclude :

Wet red litmus :

Wet blue litmus :

Conclusion :

What happens when a glass rod is dipped in concentrated HCL is brought near the mouth of gas jar containing ammonia ?

CONCLUSION

PRACTICAL USES

Ammonia is used in the manufacture of fertilizers, nitric acid, nylon fibers and in many organic chemicals.

To prepare Soap by cold process. Science practical GSEB for std 8 to 12.

Soap making practical

Soap making with Cold Process.

AIM : To prepare soap by cold process.

THEORY : Sodium hydroxide and vegetable oil reacts to give soap and the process is called saponification.

APPARATUS : Beaker, glass-rod, bunsen burner, mould, wire gauze, Sodium hydroxide, vegetable oil, Soap, Sodium hydroxide, vegetable oil, Salt,

CHEMICALS : Sodium hydroxide, vegetable oil (castor oil) and salt.

Soap making with cold process

Observation :

Conclusion :

Uses : Soap is used to remove dirt from the surface of clothes.

For more details view Video :

Soap making with Cold Process.

MEASUREMENT OF RESISTANCE ( WHEATSTONE’S BRIDGE) gseb std 11 & 12 physics practical.

Wheatstone's bridge

MEASUREMENT OF RESISTANCE

( WHEATSTONE’S BRIDGE)

Condition (1) :- MEASUREMENT OF RESISTANCE

AIM :-

You are given a Wheatstone bridge and other necessary instruments. Find the values of the unknown resistance Rx. Exchange the positions of unknown resistance and resistance box in the gaps of Wheatstone bridge and repeat the experiment.

PRINCIPLE :-

It works on the principle of balanced Wheatstone bridge.

Apparatus :-

Wheatstone-bridge (meter-bridge),

2 Volt Battery,

Rheostat,

Galvanometer,

Jockey,

Key,

Resistance box(1 – 100 W),

Resistance coil.

Precautions

Make proper and tight connections.
Keep the keys tightly closed in the resistance box.
Adjust the value of resistance box so that null point is obtained between 40 cm and 60 cm.
Do not slide the jokey continuously over the wire.

Note :- Keep high resistance of rheostat in the beginning of each observation so that current is less and the galvanometer is not damaged. After getting approximate position of null point only decrease the resistance of rheostat.