AIM:- I) to Measure by Using Vernier Callipers, the Diameter of a Spherical

ASHOKA JUNIOR COLLEGE

GRADE XI

EXPERIMENT NO:-

AIM:- i) To measure by using Vernier Callipers, the diameter of a spherical

body and calculate Volume with appropriate significant figures.

ii) To measure the volume using a graduated cylinder and compare it

with calculated value.

APPARATURS: - A pair of vernier Callipers, spherical body, a 250 ml capacity

graduated cylinder and a beaker.

FORMULA: - V = 4/3 πr3

FIGURE:-

OBSERVATIONS:-

a) LEAST COUNT (VERNIER CONSTANT)

Length of the smallest division on the main scale ,S = 1 mm

10 vernier scale division = 9 main scale of divisions

10 V = 9 S

1V = 9/10 S

V.C = 1S – 1V

= 1S – 9/10 S

= {1-9/10} S

= 1/10 S

But S = 1 mm

V.C = 1/10 mm

= 0.1 mm

= 0.01 cm

Zero error = (i) ------cm ,(ii) ------cm ,(iii) ------cm

Mean Zero error (e) = ------cm

b) Measurement of volume of spherical body by using graduated cylinder.

i) Range of graduated cylinder = ------ml

ii) No.of divisions between 10 ml and 20 ml graduations = ------n

iii) Least count of the scale graduated cylinder = ------ml/div

OBSERVATION TABLE

Table for measurement of diameter:

Observations for / M.S.R
X cm / No.of vernier division coinciding V.S.R / V.S.R x L.C
Y / Total Reading
X+ Y / Mean Observed D0 cm / Mean corrected D = D0 +(-e)
cm
Diameter I / 1)
2)
3) / D1 =
DiameterII / 1)
2)
3) / D2 =
DiameterIII / 1)
2)
3) / D3 =

1) Table for measurement of volume of the spherical ball:

No of Obs / Initial Reading of water level Vi ml / Final reading after dropping sphere Vf ml / Volume of Spherical Object V1 = Vf – Vi ml / Mean V1 ml
1)
2)
3)

CALCULATIONS :

1) Mean Corrected Diameter ,

D= D1 +D2 +D3 / 3 = ______cm

Mean corrected radius of sphere ,R = D/2 = ______cm

Volume of sphere , V0 = 4/3 πR3 = ______cm3

2) Volume as measured by graduated cylinder ,V1 ( mean value ) = ______ml

Percentage variation in volume measured with calculated value =

= V0 – V1 /V0 x 100

= ____%

RESULT :-

The diameter of the given glass marble is ______cm .

ASHOKA JUNIOR COLLEGE

GRADE XI

EXPERIMENT NO:-

AIM: - To measure the diameter of a given wire using a screw gauge and

determine percentage error in Cross –sectional area.

APPARATURS: - Screw gauge, a thin wire of known s.w.g, and a metre scale.

FORMULA: - AREA = a = π (d2/4)

OBSERVATIONS :-

Number of complete rotations of the circular scale , y = ______

Distance moved by the screw , x = ______mm

Pitch (p) , x/y = ______mm

Total Number of divisions on the circular scale ,N = ______

Least count, p/N = ______mm

Zero error = (i) ------cm ,(ii) ------cm ,(iii) ------cm

Mean Zero error (e) = ------cm

OBSERVATION TABLE :

1) Measurement of the Diameter of the wire

No of Obs / Reading along one direction(d1) / Reading along the perpendicular direction (d2) / Observed diameter d’= d1+d2/2
mm
Pitch scale reading (M)mm / No. Of C.S.R (n) / Diameter (d1) = M+n(L.C)
mm / Pitch scale reading (M) mm / No. Of C.S.R (n) / Diameter (d2) = M’+n’(L.C)
mm
1 / d’1
2 / d’2
3 / d’3

CALCULATIONS:-

Mean diameter, d0 = d1+d2+d3/3 = ______mm

Mean corrected diameter = (d0 + e) = ______mm

Area of cross-section of wire = a = π (d2/4) = ______mm2

RESULT: - The diameter of the given wire as measured by using screw gauge = ______mm

ASHOKA JUNIOR COLLEGE

GRADE XI

EXPERIMENT NO

AIM: - To measure the radius of curvature of a given spherical surface –a convex

mirror or a watch glass by using a spherometer.

APPARATURS: - A spherometer, a plane glass plate and spherical surface convex

mirror .

FORMULA: - R = l2/6h + h/2

OBSERVATIONS:-

Value of smallest division on main scale = ______mm

Distance moved by the screw in x complete rotations of the disc

i.e. y = _____mm

Pitch of the of the screw p = y/x = ______mm

Total number of divisions on the circular scale (N) = ______

Least count = p/N = ______mm

Distance between the fixed legs

i) AB = ______cm ii) BC = ______cm iii) CA = ______cm

Mean distance between any two fixed legs

l = (AB + BC + CA) /3 = ______cm

OBSERVATION TABLE:

No of Obs / Reading of the circular scale on the convex surface (1) / Reading on the plane glass plate / Fractional rotation = diff between (1) and(2) = n div / h = m x p + n x L.C (mm)
No of complete rotations (m) / Circular scale reading

Mean h =____mm

= ____cm

CALCULATIONS:-

Substitute the value of h and l in the formula

R = l2/6h + h/2

RESULT:- The radius of curvature of given spherical surface of the convex mirror

= ______cm

ASHOKA JUNIOR COLLEGE

GRADE XI

EXPERIMENT NO

AIM: - To verify the law of parallelogram of forces and determine the weight of

a body ( given wooden block).

APPARATURS: - A vertical wooden board with two pulleys, slotted Weights &

slab with a hook on its side ,a string , four sheets of paper ,

drawing pins ,set square ,protractor.

FORMULA: - R = √ P2 + Q2 + 2PQ cosθ

OBSERVATIONS:- Weight of each hanger = ______gm

Scale 1 cm = _____ gm

OBSERVATION TABLE :-

No of Obs / Magnitude of force P = wt .of hanger + slotted wts / Magnitude of force Q = wt .of hanger + slotted wts / Length OC = L (cm) / Unknown wt.X = L x S (g.wt) / Angle COC’

CALCULATIONS:- Mean value of unknown weight (X) = ______g.wt

Corrected weight, W = W0 + (-e) = ______g.wt

Percentage error = W-X/W x 100

= _____ %

RESULT: - i) The weight of the standard weights as determined by using the law of

Parallelogram of forces is same as engraved on it .Hence the law stands

Verified.

ASHOKA JUNIOR COLLEGE

GRADE XI

EXPERIMENT NO

AIM: - To find the downward force acting, along an inclined plane, acting on a roller

due to gravitational pull of the earth and to study its relationship with the

angle of inclination by plotting graph between force and sinθ.

APPARATURS: - An inclined plane with a glass top and a pulley, the plane is

hinged to a wooden horizontal slotted board provided with

metallic quadrant to measure angle of inclination ,a roller, strong

thread ,a pan ,half metre scale ,a spring balance ,weight box &

spirit level.

OBSERVATIONS:- Least count of the spring balance = ______g wt

Observed weight of pan (P0) = ______g wt

Corrected weight of pan ( P) = P0 + (-e) = ____g wt.

Observed weight of roller W0 . = ______g wt.

Corrected weight of roller W = W0 + (-e) = ____g wt.

OBSERVATION TABLE:-

S.No / Angle ofinclinationθ / Weight placed in pan / F1 = P + W1
g wt. / F2 = P + W2
g wt. / Componenet of gravitational pull on roller
F = F1+ F2
2 / sin θ / W sin θ / F- sin θ
g wt.
Down ward W1 (g wt). / Upward W2
g wt.
1 / 30
2 / 35
3 / 40
4 / 45
5 / 50

GRAPH: - Plot a graph of F vs. θ & F vs. sin θ

RESULT:- Within the limits of experimental error ,the downward force F along the inclined plane on

the roller on account of the gravitational pull is F = mg sin θ