Physics Practicals - For Class X (Science Group) - PRACTICAL 01: To measure the Length and Diameter of a solid cylinder with Vernier Calliper.

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PRACTICAL 01:

To measure the Length and Diameter of a solid cylinder with Vernier Calliper.

APPARATUS:

• Vernier Callipers
• Solid Cylinders

THEORY:
VERNIER CALLIPERS:
It consists of a pair of callipers in which one is fixed having a scale which is called main scale while other is moveable having a scale which is known as vernier scale and has 10 division. It can be measure accurately upto 0.01 cm.

LEAST COUNT:
Less possible length that can he measured by Vernier callipers is called its least count.

ZERO ERROR:
When two jaws of vernier callipers are in contact and zero of main scale does not coincide with the zero of the vernier scale, vernier callipers is said to have zero error. It is positive when zero of vernier is on the right of the main scale and negative when zero of the vernier is on the left of main scale.

FORMULA: (1 MARK)
Volume of cylinder = area of cross section x length

V = πr²l

METHOD:
First see that apparatus have zero error or not. Calculate least count of vernier callipers.

MEASUREMENT OF DIAMETER:

• Fix the cylinder diameter - wise between the two jaws of vernier calliper.
• Note main scale reading and vernier scale reading.
• Find fractional part by multiplying vernier scale reading and least count.
• Add main scale reading and fractional part to get total length. If zero error is present then correct the reading.
• Take three sets of readings.

MEASUREMENT OF LENGTH:

• Fix the cylinder length - wise between the two jaws of Vernier calliper.
• Take three sets of reading as taken for the diameter.

OBSERVATION:
Length of one main scale division = 1 mm = 0.1 cm
Total no. of vernier scale division = 10
Least count = Length of one M.S division / No. of V.S division
L.C. = 0.1 / 10
L.C. = 0.01 cm
Zero error = + --------- cm

LENGTH OF CYLINDER: (2 MARKS)

OBS	MAIN SCALE READING (M.S.R.) cm	VERNIER SCALE READING (V.S.R.) div	FRACTIONAL PART F.P. = V.S.R. x L.C cm	TOTAL LENGTH L =M.S.R. + F.P. cm	CORRECTED LENGTH +Z.E.
	3.2 cm	4 div	4 x 0.01 = 0.04 cm	3.2 + 0.04 = 3.24 cm
1.
2.
3.

DIAMETER OF CYLINDER: (2 MARKS)

OBS	MAIN SCALE READING (M.S.R.) cm	VERNIER SCALE READING (V.S.R.) div	FRACTIONAL PART F.P. = V.S.R. x L.C cm	TOTAL LENGTH L =M.S.R. + F.P. cm	CORRECTED DIAMETER D + Z.E.
1.
2.
3.

RESULT:
Length of the cylinder is ----------- cm
Diameter of the cylinder is -------- cm
Volume of the cylinder is ----------- cm³

FIGURE: (2 MARKS)

PRECAUTIONS:
Jaws must not be pressed very tightly.
Cylinder must not held firmly so that it does not move.

Special Thanks to Sir Sajjad Akber Chandio

Physics Practicals - For Class IX (Science Group) - PRACTICAL 06: To draw a Graph between volume and height of the water in a graduated cylinder.

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PRACTICAL 06:

To draw a Graph between volume and height of the water in a graduated cylinder.

APPARATUS:

• Graduated cylinder
• Beaker
• Dropper Or Pipette
• Scale
• Water
• Rubber band

THEORY:
The volume of a liquid in a graduated cylinder is directly proportional to the height of the liquid, therefore the ratio between height and volume is constant and graph between them will be a straight line.

MATHEMATICALLY:

V ∝ h

V = (constant) h

V/ h = constant

GRADUATED CYLINDER:
It is a cylinder of uniform diameter calibrated in millimetre or centimetre.

VOLUME:
Space occupied by a body is called volume. In S.I. system its unit is m³ and in C.G.S system its unit is cm^-3 or ml.

FORMULA:

V = πr^-3h

METHOD: (2 Marks)

1. Rinse the cylinder with water so that no dust particles remain in it.
2. Fix the scale vertically with the wall of cylinder such that its zero coincide with 10 ml. mark of cylinder.
3. Slowly pour water into cylinder such that the lower meniscus of water coincide with 20 ml. mark.
4. Note down height of water.
5. Add more water in the cylinder and take five readings of volume and corresponding height of volume.

OBSERVATION:

No.	VOLUME OF WATER (V) ml	HEIGHT OF WATER (h) cm	V/h ml /cm
1.	20
2.	30
3.	40
4.	50
5.	60

GRAPH: (3 MARKS)

• Draw x and y-axis on the graph paper. Take Volume 'V' on x-axis and Length 'h' is on y-axis.
• Supply suitable scale.
• Plot values of 'V' and 'h' from observation column.
• Draw line, which join those points.

(Note: This is a sample graph with assuming readings. The graph should be in a straight line if correct readings are obtained.)


FIGURE: (1 Marks)


RESULT: (0.5 Marks)
Since ratio between "V" and "h" is constant and graph between V and h is a straight line therefore volume and height are directly proportional to each other.

PRECAUTIONS:

• Cylinder must be rinsed before use.
• Attach scale vertically with cylinder.
• Cylinder must be placed on the horizontal surface.
• There should be no air bubble in the cylinder.

Special Thanks to Sir Sajjad Akber Chandio

Physics Practicals - For Class IX and X (Science Group) - PRACTICAL 04(X) 05(IX): Find the Specific Gravity of a body heavier than water by Archimedes principle.

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PRACTICAL 04(X) 05(IX):

Find the Specific Gravity of a body heavier than water by Archimedes principle.

APPARATUS:

• Physical balance
• Weight box
• Insoluble solid
• Beaker
• Water
• Bench
• Thread

THEORY:
ARCHIMEDES'S PRINCIPLE:
When a body is partially or wholly immersed in a liquid, due to upthrust it appears to lose some of its weight. The loss in weight of !he body is equal to the weigh of the liquid displaced.

SPECIFIC GRAVITY OR RELATIVE DENSITY:
It is the ratio of density of the substance to the density of water at 4 °C.

METHOD: (2 Marks)

• Adjust the balance with the help of adjusting and leveling screw.
• Suspend the bob in left-hand pan with thread.
• Find the weight of bob in air.
• Place a wooden bridge across left pan and place a beaker containing water.
• Find Weight of bob in water such that it does not touches the side wall of beaker. Bob should remain in water when beam is raised.

OBSERVATIONS: (5 Marks)

OBS.	WEIGHT OF SOLID IN AIR W1 (gm-wt)	WEIGHT OF SOLID IN WATER W2 (gm-wt)	LOSS OF WEIGHT OF SOLID IN WATER W1 - W2 (gm-wt)

CALCULATIONS:
FORMULA (1 Mark)

Specific gravity = ----------------- = --------------------

RESULT:
Specific gravity of given solid is found to be = ----------

FIGURE: (2 Mark)

PRECAUTIONS:

• Physical balance must be adjusted.
• Pan must not touch the wooden bench.
• Use foreceps to take weights from the weight box.

Special Thanks to Sir Sajjad Akber Chandio

Physics Practicals - For Class IX and X (Science Group) - PRACTICAL 02: Determine the Resultant of two vectors by (Gravesend's apparatus).

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PRACTICAL 02:

• Determine the Resultant of two vectors by (Gravesend's apparatus).

APPARATUS:

• Gravesend's Apparatus i.e:
  i) Vertical drawing board
  ii) Two fixed pulleys (clamped to the top)
• Three sets of 20 gm slotted weights with hanger
• Plane mirror strip
• Drawing paper
• Thumb pin
• Light string about 1 meter long
• Meter Scale
• Geometry box

THEORY:
Those physical quantities, which are completely, specified only when direction is also mentioned along with magnitude and units are known as vector.

RESULTANT VECTOR:
Vectors, which gives combined effect of two or more vectors, called resultant vectors.

TRIANGULAR LAW OF VECTOR ADDITION:
If two vectors represent two sides of the triangle, then third side of triangle in reverse order will be the resultant of the two sides.

PARALLELOGRAM LAW OF VICTOR ADDITIONS:
According to this law the diagonal of parallelogram represents the resultant of two adjacent of the parallelogram.

METHOD: (1 + 1 MARKS)

• Fix drawing paper in the middle of the vector board and place it vertically.
• Adjust the thread, carrying a set of weights at each end, over two pulleys.
• The small thread carrying third set of weights at the center of the first two thread.
• Place plane mirror under one of the thread keeping one eye close and mark two points 'A' and 'B', such that the two points and the image of thread lie exactly under the thread.
• Similarly mark C, D and E, F under other two thread.
• Join A and B, C and D. and E and F and extend them to meet at point O.
• Select suitable scale (10 gm-wt = 1 cm) and draw arcs OP and OQ corresponding to their weights.
• Draw PX and QX parallel to OP and OQ.
• Join P and X and 0 and X.
• OX is the resultant of OP and PX.
• Find magnitude of OX by multiplying its length with the scale.
• Repeat above procedure by using unequal weights and find their resultant.

OBSERVATIONS: (1 + 1 MARKS)

OBS	WEIGHT OF RIGHT HAND SIDE (OP) gm-wt	WEIGHT OF LEFT HAND SIDE (OQ) gm-wt	RESULTANT WEIGHT (OX) gm-wt
1.
2.

FIGURE:

RESULT:
1. The magnitude of the resultant of two equal vectors each of ______ is _______ gm-wt.
2. The magnitude of two unequal vectors of _______ gm-wt and _______ is ______ gm-wt.

PRECAUTIONS:

• Board must be exactly vertical.
• Standard weights must be used.
• Pulleys must be friction less.

Special Thanks to Sir Sajjad Akber Chandio