Practical Physics

Find the volume of the given rectangular glass plate using vernier calipers and screw gauge.

2009-03-11T08:50:00.000-07:00

Formulae:

i) Least count of vernier calipers (L.C) = mm,

S = value of 1 Main scale division , N = Number of vernier divisions.

ii ) Total reading = Main scale reading (a) mm + ( n*L.C ) mm

iii) Pitch of the screw =

iv) Least count of Screw gauge (L.C) =

v) Total Reading = P.S.R + ,

P.S.R = Pitch scale reading , n= Corrected Head scale reading , L.C = Least count

vi) Volume of the glass plate V =

l = length of the glass plate, b = breadth of glass plate , h = Thickness of glass plate.

Procedure :First we have to determine the least count count of the given vernier calipers.

From the given vernier calipers

S= Length of Main scale division = 1 mm = 0.1 cm,

N = Number of vernier scale divisions = 10 ,

Substitute these values in the formula of Least count L.C = = =0.01 cm.

Draw neat diagram of Vernier calipers

Part I : To determine the length ( l )and breadth (b) of the given glass plate with vernier calipers :The given glass plate is held between two jaws of vernier calipers, first to measure its length.Note down the values of the Main scale reading (M.S.R ) and vernier coincidence (VC) in Table-I, take 3set of readings by placing the glass plate in 3 different positions.Each time calculate the total reading by substituting the values of M.S.R and VC in the formula Total reading = M.S.R + (.

Find the average of 3readings and calculate Average Length ( l )of the given glass plate.

Now hold the glass plate between jaws of vernier calipers breadth wise ,repeat the experiment as above , note down the 3 set of readings of M.S.R and VC in Table-II.Calculate average breadth (b) of the glass plate

Part II: To determine thickness(h) of glass plate using Screw gauge:First we have to determine the least count of the given Screw gauge.

Number of complete rotations of the screw = 5

Distance moved by sloped edge over the pitch scale = 5mm

Pitch of the screw = = =1mm.

Number of divisions on the head scale = 100

Least count (L.C) = = =0.01mm

Draw neat diagram of Screw Gauge

Zero Error :Now check whether the given screw gauge has any ZERO ERROR or not. To determine the ZERO ERROR, the head H is rotated until the flat end of the screw touches the plane surface of the stud (do not apply excess pressure) i.e we have to rotate the head only by means of safety device ‘D’ only.

When and are in contact,the zero of the head scale perfectly coincides with the index line as in Fig-(a). In such case there will be no ZERO ERROR and no correction is required.

When and are in contact,the zero of the head scale is below the index line as in Fig(b), such ZERO ERROR is called positive ZERO ERROR, and the correction is negative.

When and are in contact,the zero of the head scale is above the index line as in Fig(c) , such ZERO ERROR is called negative ZERO ERROR, and the correction is positive.

When and are in contact,98 th division of head scale is coinciding with index line i.e the zero of the head scale is 3 divisions below the index line as in Fig(b), such ZERO ERROR is called positive ZERO ERROR, and the correction is negative.

The Zero correction for the given screw gauge = - 2

The given glass plate is held between the two parallel surfaces of fix stud and screw tip . Note the completed number of divisions on pitch scale, which is called PITCH SCALE READING (P.S.R). The number of the head scale division coinciding with the index line is noted, which is called OBSERVED HEAD SCALE READING n’. If the given screw gauge has ZERO ERROR (x) the correction is made by adding or subtracting the ZERO ERROR (x) from the OBSERVED HEAD SCALE READING n’.The corrected value (n’-x) or (n’+x) is called the HEAD SCALE READING (H.S.R) n.

To calculate the fraction the H.S.R (n) is multiplied by the least count (L.C).

Diameter of first wire = Total reading = P.S.R + - - - - - - (1)

Changing the position of the glass plate, 3 readings should be taken, and recorded in the table-III. Every time calculate the total thickness (h)of glass plate using equation (1).

Calculate average of 3readings which is average thickness (h) of glass plate.

Table-I: Length (l) of the glass plate :

S.No	M.S.R a cm	Vernier Coincidence (n)	Fraction b=n*L.C	Total Reading (a+b) cm
1	2.5	8	0.01*8=0.08	2.58
2	2.5	9	0.01*9=0.09	2.59
3	2.5	7	0.01*7=0.07	2.57

Average length of glass plate (l) = = = 2.58 cm

Average length of glass plate (l) = 2.58 cm or 25.8mm

Table-II: Breadth (b)of the glass plate :

S.No	M.S.R a cm	Vernier Coincidence (n)	Fraction b=n*L.C	Total Reading (a+b) cm
1	1.1	4	0.01*4=0.04	1.14
2	1.1	5	0.01*5=0.05	1.15
3	1.1	5	0.01*5=0.05	1.15

Average Breadth of glass plate (b) = = = 1.15 cm.

Average Breadth of glass plate (b) = 1.15 cm or 11.5 mm.

Table-III: Thickness (h)of the glass plate :

S.No	Pitch Scale Reading (P.S.R) amm	Observed H.S.R (n’)	Correction (x)	Corrected H.S.R n=n’(+/-)x	Fraction b=n*L.C	Total reading (a+b) mm
1	2	75	2	75-2=73	73*0.01=0.73	2.73
2	2	74	2	74-2=72	72*0.01=0.72	2.72
3	2	76	2	76-2=74	74*0.01=0.74	2.74

Average Thickness (h) of glass plate (b) = = = 2.73 mm.

Average Thickness of glass plate (h) = 2.73 mm.

Observations :

i)Average length of glass plate (l) = 2.58 cm or 25.8mm

ii)Average Breadth of glass plate (b) = 1.15 cm or 11.5 mm.

iii)Average Thickness of glass plate (h) = 2.73 mm.

Calculations : Volume of the given glass plate V =

Volume of the given glass plate V = =809.99

Precautions :

1) Take the M.S.R and vernier coincide every time without parallax error.

2)Record all the reading in same system preferably in C.G.S system.

3) Do not apply excess pressure on the body held between the jaws.

4) Check for the ZERO error.When the two jaws of the vernier are in contact,if the zero division of the main scale coincides with the zero of the vernier scale no ZERO error will be there.If not ZERO error will be there, apply correction.

5) Pitch scale reading (P.S.R) should be taken carefully without parallax error

6) Head scale reading (H.S.R) should be taken carefully without parallax error

7)Screw must be rotated by holding the safety device ‘D’

8 ) Do not apply excess pressure on the object held between the surfaces and .

Result : Volume of the given glass plate is V= 809.99

Vernier Calipers
Screw Gauge
Spherometer
Physical Balence
Simple pendulum
Concurrent Forces
Boyle's Law
Specific Heat
Apparent Expansion of liquid
Surface Tension
Velocity of sound
Refractive Index (I - D Curve )
Concave Mirror
Convex Lens
Magnetic Field - Null points
Deflection Magnetometer
Ohm's Law
Tangent Galvanometer
Metre Bridge
Junction Diode ( I - V Charecteristics )
Pattern of Question paper (Scheme of Valuation)
Question Bank

Compare the radii of given three wires using Screw Gauge.

2009-03-04T09:18:00.000-08:00

Formulae :

i ) Pitch of the screw = .

ii ) Least count (L.C) = ,

iii ) Total Reading = P.S.R + ,

P.S.R = Pitch scale reading , n= Corrected Head scale reading , L.C = Least count

iv ) Ratio of radii of the three given wires is ::,

where = Average radius of first wire,

= Average radius of second wire,

= Average radius of third wire.

Draw figure

Procedure :First we have to determine the least count of the given Screw gauge.

To determine the least count of the screw gauge, the head ‘H’ is rotated through certain (say 5) number of complete rotations.The distance moved by the sloped edge over the pitch scale is measured.

Now substitute these values in the formula of pitch of the screw = .

Least count L.C = .

Now check whether the given screw gauge has any ZERO ERROR or not. To determine the ZERO ERROR, the head H is rotated until the flat end of the screw touches the plane surface of the stud (do not apply excess pressure) i.e we have to rotate the head only by means of safety device ‘D’ only.

When and are in contact,the zero of the head scale perfectly coincides with the index line as in Fig-(a). In such case there will be no ZERO ERROR and no correction is required.

When and are in contact,the zero of the head scale is below the index line as in Fig(b), such ZERO ERROR is called positive ZERO ERROR, and the correction is negative.

When and are in contact,the zero of the head scale is above the index line as in Fig(c) , such ZERO ERROR is called negative ZERO ERROR, and the correction is positive.

Determine the radii of the given metal wires :The given object metal wire is held between the two parallel surfaces of fix stud and screw tip . Note the completed number of divisions on pitch scale, which is called PITCH SCALE READING (P.S.R). The number of the head scale division coinciding with the index line is noted, which is called OBSERVED HEAD SCALE READING n’. If the given screw gauge has ZERO ERROR (x) the correction is made by adding or subtracting the ZERO ERROR (x) from the OBSERVED HEAD SCALE READING n’.The corrected value (n’-x) or (n’+x) is called the HEAD SCALE READING (H.S.R) n.

To calculate the fraction the H.S.R (n) is multiplied by the least count (L.C).

Diameter of first wire = Total reading = P.S.R + - - - - - - (1)

Changing the position of metal wire, 5 readings should be taken, and recorded in the table-1. Every time calculate the total diameter (d) of the metal wire using equation (1).

Average of the 5 diameter of the metal wire should be calculated, to get the average diameter(d) of the first metal wire.

Radius () of the first metal wire = mm.

The diameters of 2nd and 3rd wires are also measured following the above procedure. From diameters of 2nd and 3rd wires we can calculate their radii and .

Calculation of least count:

Number of complete rotations of the screw = 5

Distance moved by sloped edge over the pitch scale = 5mm

Pitch of the screw = = =1mm.

Number of divisions on the head scale = 100

Least count (L.C) = = =0.01mm

Zero Error :

When and are in contact,97 th division of head scale is coinciding with index line i.e the zero of the head scale is 3 divisions below the index line as in Fig(b), such ZERO ERROR is called positive ZERO ERROR, and the correction is negative.

The Zero correction for the given screw gauge = - 3

Table -1 ( Diameter of the 1st wire) :

S.No	Pitch Scale Reading (P.S.R) amm	Observed H.S.R (n’)	Correction (x)	Corrected H.S.R n=n’(+/-)x	Fraction b=n*L.C	Total reading (a+b) mm
1.	1	45	3	45-3=42	42*.001=0.42	1.42
2.	1	46	3	46-3=43	43*0.01=0.43	1.43
3.	1	46	3	46-3=43	43*0.01=0.43	1.43
4.	1	47	3	47-3=44	44*.001=0.44	1.44
5.	1	46	3	46-3=43	43*0.01=0.43	1.43

Average diameter of the 1st wire () = = mm.

Average diameter of the 1st wire () = 1.43 mm

Average radius of 1st wire () = = =0.72 mm

Table - 2 (Diameter of the 2nd wire):

S.No	Pitch Scale Reading (P.S.R) amm	Observed H.S.R (n’)	Correction (x)	Corrected H.S.R n=n’(+/-)x	Fraction b=n*L.C	Total reading (a+b) mm
1.	2	12	3	12-3=9	9*0.01=0.09	2.09
2.	2	13	3	13-3=10	10*0.01=0.10	2.10
3.	2	14	3	14-3=11	11*0.01=0.11	2.11
4.	2	12	3	12-3=9	9*0.01=0.09	2.09
5.	2	14	3	14-3=11	11*0.01=0.11	2.11

Average diameter of the 1st wire () = = mm.

Average diameter of the 2nd wire () = 2.10 mm

Average radius of 2nd wire () = = =1.05 mm

Table -3 ( Diameter of the 3rd wire) :

S.No	Pitch Scale Reading (P.S.R) amm	Observed H.S.R (n’)	Correction (x)	Corrected H.S.R n=n’(+/-)x	Fraction b=n*L.C	Total reading (a+b) mm
1.	1	85	3	85-3=82	82*0.01=0.82	1.82
2.	1	84	3	84-3=81	81*0.01=0.81	1.81
3.	1	84	3	84-3=81	81*0.01=0.81	1.81
4.	1	86	3	86-3=83	83*0.01=0.83	1.83
5.	1	86	3	86-3=83	83*0.01=0.83	1.83

Average diameter of the 1st wire () = = mm.

Average diameter of the 3rd wire () = 1.82 mm

Average radius of 3rd wire () = = =0.91 mm

Observations : i)Average radius of 1st wire () = 0.72 mm,

ii)Average radius of 2nd wire () = 1.05 mm

iii )Average radius of 3rd wire () = 0.91 mm.

Precautions : i ) Pitch scale reading (P.S.R) should be taken carefully without parallax error ii ) Head scale reading (H.S.R) should be taken carefully without parallax error iii )Screw must be rotated by holding the safety device ‘D’ iv ) Do not apply excess pressure on the object held between the surfaces and .

v ) The screw is rotated in only one direction either clock wise or anti-clock wise to avoid the back lash error.

Result : Ratio of radii of the given wires is :: = 0.72 : 1.05 : 0.91

Screw Gauge

2009-02-18T01:39:00.000-08:00

Experiment No :2

Aim: To measure the i)Thickness of the Glass Plate ii) Diameter of the metal wire iii) Volume of the given Glass Plate.

Apparatus : Screw Gauge , Glass Plate and Metal wire .

Description : Screw Gauge consists of U shaped metallic frame.To one side of this U frame a long hallow cylindrical tube with a nut inside it, the inner side of cylindrical nut contains a uniform thread cut in it.On the other side of U frame a fixed stud with a plane face is attached.

A screw is fitted in the cylindrical nut.One side of the screw has a plane face similar to that of stud . The faces of and are plane and parallel to one another. The other end of the screw carries a milled head ‘H’ attached to a cap ‘C’ with a sloping edge. When the head H is rotated, the screw moves ”to and fro” in the nut.The milled head H is provided with a safety device ‘D’ to rotate the head H.When the object is held between the stud and screw and the head H is rotated using the safety device (D), it produces crackling sound when optimum pressure is applied on the object.

The outer surface of long cylindrical nut consists of a thick horizontal line ‘P’ parallel to the axis of cylindrical tube.This line ‘P’ is called Index line. Along the index line a scale is graduated in millimeters.This scale is called Pitch Scale.On the sloping edge of the cap ‘C’ a circular scale is graduated, which consists of 100 equal divisions, this scale is called Head scale.

Theory : The screw gauge works on the principle of screw.

When we rotate the head ‘H’ by means of safety device ‘D’ through one complete rotation, the distance moved by the screw for every complete rotation is constant. This constant distance moved by the screw for one complete rotation of head ‘ H ‘ is called Pitch of the screw.If the head scale has 100 equal divisions, then the distance moved by the screw for even 1/100 of a complete rotation can be measured accurately,this is called Least count of screw gauge.

Therefore Least count (L.C) = .

Procedure :First we have to determine the least count of the given Screw gauge.

Now substitute these values in the formula of pitch of the screw = .

Least count L.C = .

When and are in contact,the zero of the head scale perfectly coincides with the index line as in Fig-(a). In such case there will be no ZERO ERROR and no correction is required.

When and are in contact,the zero of the head scale is below the index line as in Fig(b), such ZERO ERROR is called positive ZERO ERROR, and the correction is negative.

When and are in contact,the zero of the head scale is above the index line as in Fig(c) , such ZERO ERROR is called negative ZERO ERROR, and the correction is positive.

a) Determine the thickness of glass plate : The given object glass plate is held between the two parallel surfaces of fix stud and screw tip . Note the completed number of divisions on pitch scale, which is called PITCH SCALE READING (P.S.R). The number of the head scale division coinciding with the index line is noted, which is called OBSERVED HEAD SCALE READING n’. If the given screw gauge has ZERO ERROR (x) the correction is made by adding or subtracting the ZERO ERROR (x) from the OBSERVED HEAD SCALE READING n’.The corrected value (n’-x) or (n’+x) is called the HEAD SCALE READING (H.S.R) n.

To calculate the fraction the H.S.R (n) is multiplied by the least count (L.C).

Thickness of the Glass plate = Total reading = P.S.R + - - - - - (1)

Changing the position of glass plate , 5 readings should be taken, and recorded in the table-1. Every time calculate the total thickness of the glass plate using equation (1).

Average of the 5 readings of the glass plate should be calculated, to get the average thickness(t) of the given glass plate.

b) Determine the radius(r) of the given metal wire :The given object metal wire is held between the two parallel surfaces of fix stud and screw tip . Note the completed number of divisions on pitch scale, which is called PITCH SCALE READING (P.S.R). The number of the head scale division coinciding with the index line is noted, which is called OBSERVED HEAD SCALE READING n’. If the given screw gauge has ZERO ERROR (x) the correction is made by adding or subtracting the ZERO ERROR (x) from the OBSERVED HEAD SCALE READING n’.The corrected value (n’-x) or (n’+x) is called the HEAD SCALE READING (H.S.R) n.

To calculate the fraction the H.S.R (n) is multiplied by the least count (L.C).

Diameter of the given metal wire = Total reading = P.S.R +

Changing the position of metal wire, 5 readings should be taken, and recorded in the table-2. Every time calculate the total diameter (d) of the metal wire using equation (1).

Average of the 5 diameter of the metal wire should be calculated, to get the average diameter(d) of the given metal wire.

Radius (r) of the metal wire = mm.

v ) The screw is rotated in only one direction either clock wise or anti-clock wise to avoid the back lash error.

Observations : i ) Zero error =

ii) Zero correction = ...... mm

iii ) Distance moved by the head for 5 complete revolutions = mm

iv ) Number of head scale divisions =

v) Pitch of the screw =

vi) Least count (L.C) = .

Table -1 ( Thickness of glass plate ) :

S.No

Pitch Scale Reading (P.S.R) amm

Observed H.S.R (n’)

Correction (x)

Corrected H.S.R n=n’-x

Fraction b=n*L.C

Total reading (a+b) mm

1.

2.

3.

4.

5.

Average thickness of the glass plate (t) = ..... mm

Table - 2 (Diameter of the metal wire):

S.No

Pitch Scale Reading (P.S.R) amm

Observed H.S.R (n’)

Correction (x)

Corrected H.S.R n=n’-x

Fraction b=n*L.C

Total reading (a+b) mm

1.

2.

3.

4.

5.

Average diameter d = .... mm

Average radius r = = .... mm .

c ) Volume of Glass plate (v) : The length ( l ) , breadth ( b) are determined using vernier calipers and thickness ( t ) of the glass plate is determined using screw gauge. The values of l ,b and t are substituted in the equation of volume V = ( l )( b )( t )

Find the volume of the Sphere - Vernier Calipers.

2009-02-13T01:03:00.000-08:00

2 Q : Find the volume of the given sphere using vernier calipers.

Ans:

Formula :

1. Volume of the Sphere V = ,

V= volume of Sphere, r = radius of Sphere
.

2.Least count of vernier calipers L.C = cm,

S = value of 1 Main scale division , N = Number of vernier divisions.

3.Length (or) diameter of Cylinder = Main scale reading (a) cm + ( n*L.C ) cm.

n = vernier coincidence .

Draw Figure

Procedure : First we have to determine the least count count of the given vernier calipers.

To determine the volume of the Sphere we have to determine the radius (r) of the cylinder and substituting this value in the equation for the volume of the Sphere we can calculate it.

a) To determine the diameter of the Sphere : Given Sphere is held gently between jaws 1,1 of the vernier calipers.The reading on the main scale just before the zero of the vernier is noted.This is called Main scale reading (M.S.R).The number of division (n) on the vernier which coincides perfectly with any one of the main scale divisions is noted.This is called vernier coincidence (V.C).The vernier coincidence (V.C=n) is multiplied by least count to get the fraction of a main scale division.This is added to the main scale reading (M.S.R) to total reading or total diameter of the sphere.

Total reading = M.S.R + ()

Take the readings,keeping the Sphere between jaws 1,1 at different positions.Post the values of M.S.R and vernier coincidence (n) in the table.Take at least 5 readings, get the average of these 5 readings which is mean diameter (d)of the Sphere.

Place the Sphere diametrically between the jaws 1,1 of the vernier calipers, post the values of M.S.R and vernier coincidence (n) in the table. Take at least 5 readings, calculate the average of these readings which gives the mean diameter ( d=2r ) of the Sphere.

c) To determine the volume of the Sphere :Substituting the value mean radius ( r) of the sphere which is already determined, in the formula V = ,

Determine Least count of vernier calipers : From the given vernier calipers

S= Length of Main scale division = 1 mm = 0.1 cm,

N = Number of vernier scale divisions = 10 ,

Substitute these values in the formula of Least count L.C = = =0.01 cm.

Table for Diameter of the Sphere :

S.No	M.S.R acm	Vernier Coincidence (n)	Fraction b=n*L.C	Total Reading (a+b) cm
1.	1.9	7	0.05	1.97
2.	1.9	6	0.04	1.96
3.	1.9	6	0.06	1.96
4.	1.9	7	0.05	1.97
5.	1.9	7	0.06	1.97

Average diameter of the sphere d = 2r = cm =

Average radius of the sphere r = = cm = 0.98 cm.

Observations :

Average radius of the cylinder r = 0.98 cm.

Calculations : Volume of the sphere V = =

=3.94

Precautions : 1) Take the M.S.R and vernier coincide every time without parallax error.

2)Record all the reading in same system preferably in C.G.S system.

3) Do not apply excess pressure on the body held between the jaws.

Result and Units : Volume of the sphere V = 3.94 .

Find the volume of cylinder - Vernier calipers.

2009-02-12T11:17:00.000-08:00

Q : Find the volume of the given cylinder using vernier calipers.

Ans : Draw Fig

Formula :

1. Volume of the cylinder V = ,

V= volume of cylinder, r = radius of cylinder l = length of cylinder.

2.Least count of vernier calipers L.C = cm,

S = value of 1 Main scale division , N = Number of vernier divisions.

3.Length (or) diameter of Cylinder = Main scale reading (a) cm + ( n*L.C ) cm.

n = vernier coincidence .

Procedure : First we have to determine the least count count of the given vernier calipers.

To determine the volume of the cylinder we have to determine a)the length of the cylinder and b) radius of the cylinder and substituting these values in the equation for the volume of the cylinder we can calculate it.

a) To determine the length of the cylinder : Given cylinder is held gently between jaws 1,1 of the vernier calipers.The reading on the main scale just before the zero of the vernier is noted.This is called Main scale reading (M.S.R).The number of division (n) on the vernier which coincides perfectly with any one of the main scale divisions is noted.This is called vernier coincidence (V.C).The vernier coincidence (V.C=n) is multiplied by least count to get the fraction of a main scale division.This is added to the main scale reading (M.S.R) to total reading or total length of the cylinder.

Total reading = M.S.R + ()

Take the readings,keeping the cylinders between jaws 1,1 at different positions.Post the values of M.S.R and vernier coincidence (n) in the table.Take at least 5 readings, get the average of these 5 readings which is mean length(l )of the cylinder.

b)To determine the diameter of the cylinder : Place the cylinder diametrically between the jaws 1,1 of the vernier calipers, as in the above case post the values of M.S.R and vernier coincidence (n) in the table. Take at least 5 readings, calculate the average of these readings which gives the mean diameter ( d=2r ) of the cylinder.

c) To determine the volume of the cylinder :Substituting the values of mean length (l ) of the cylinder and mean diameter ( r) of the cylinder which is already determined, in the formula V = .

Determine Least count of vernier calipers : From the given vernier calipers

S= Length of Main scale division = 1 mm = 0.1 cm,

N = Number of vernier scale divisions = 10 ,

Substitute these values in the formula of Least count L.C = = =0.01 cm.

Table - Length of the cylinder :

S.No	M.S.R acm	Vernier Coincidence (n)	Fraction b=n*L.C	Total Reading (a+b) cm
1.	2.6	9	0.09	2.69
2.	2.7	1	0.01	2.71
3.	2.7	2	0.02	2.72
4.	2.7	2	0.02	2.72
5.	2.6	8	0.08	2.68

Average length of the cylinder l = cm= = 2.70 cm

b) Diameter of the cylinder :

S.No	M.S.R acm	Vernier Coincidence (n)	Fraction b=n*L.C	Total Reading (a+b) cm
1.	1.4	5	0.05	1.45
2.	1.4	4	0.04	1.44
3.	1.4	6	0.06	1.46
4.	1.4	5	0.05	1.45
5.	1.4	6	0.06	1.46

Average diameter of the cylinder d = 2r = cm= = 1.45 cm,

Average radius of the cylinder r = = cm = 0.73 cm.

Observations :

Average length of the cylinder l = 2.70 cm,

Average radius of the cylinder r = 0.73 cm.

Calculations : Volume of the cylinder V = = = 4.52

Precautions : 1) Take the M.S.R and vernier coincide every time without parallax error.

2)Record all the reading in same system preferably in C.G.S system.

3) Do not apply excess pressure on the body held between the jaws.

Result and Units : Volume of the cylinder V = 4.52 .

Practical Exams Question bank.

2009-02-08T03:17:00.000-08:00

Physics Practical Examination

( Board of Intermediate Education, Andhrapradesh)

Question Bank

SECTION - A

1.Find the volume of given cylinder using vernier calipers.

2.Find the volume of given sphere using vernier calipers.

3.Compare the radii of given three wires using screw gauge.

4.Find the volume of the given rectangular glass plate using vernier calipers and screw gauge ( Take at least 3 observations).

5.Find the volume of given cylinder bt measuring the length with vernier calipers and radius with screw gauge.

6.Find the thickness of given glass plate and radius of curvature of given curved surface (watch glass) using spherometer.

7.Find the thickness of glass plate with spherometer and verify the result with a screw gauge.

8.Find the focal length of given sphrecal mirror with spherometer.

9.Find the mass of the given body correct to milligram using a common balance.

SECTION - B

10.Find the value of ‘g’ at a given place using a simple pendulum.Also find the percentage error in measurement.

11.Find the acceleration due to gravity at your place using simple pendulum from l - graph.Find length of seconds pendulum also.

12.Find length of seconds pendulum from l - graph.

13.Verify parallelogram law of forces.Find weight of given stone in air.

14.Verify the triangle law of forces take 3 readings).Find relative density of given stone.

15.Find the volume of the given stone using parallelogram law of forces.Take 3 observations.

16.Find the volume of the stone applying the triangle law of forces.

17.Verify Boyle’s law and draw p-l graph ( Take 8 observations).

SECTION - C

18.Verify Boyle’s law. Draw h- graph.(take 6 observations)

19.Using Boyle’s law apparatus,draw h- graph.Hence find the atmospheric pressure.

20. Find the co-efficient of apparent expansion of given liquid using the specific gravity bottle.

21.Find the co-efficient of real or absolute expansion of the given liquid using specific gravity bottle.

22.Find the specific heat of solid by method of mixtures.

23.Find the surface tension of water by capillary rise method.

24.Determine the radius of the bore of given capillary tube by capillary rise method.(T = 72 dyne/cm)

SECTION - D

25.Find the focal length of given concave mirror by u - v method.Draw u - v graph and hence find its focal length.Compare these two values.

26.Find the focal length of given concave mirror by u , v method.Verify the result from - graph method.

27.Find the focal length of given convex lens by u - v method.Verify the result from u - v graph.

28.Find the focal length of given convex lens from u - v graph.Verify result from - graph.

29.Find the focal length of given convex lens by u - v method.Verify the results from - graph.

30.Find the focal length of yhe given convex lens by lens displacement or conjugate foci method.

31.For a prism , assuming the angle of the Prism as ,draw I-d curve and hence determine the refractive index of material of the prism.

32.Draw I-d curve and determine the angle of the prism assuming refractive index of glass as 1.5 .

SECTION - E

33. Find velocity of sound in air at room temperature.(using 3 tuning forks) and estimate its value at C.

34.Compare the frequencies of the given two tuning forks using resonance apparatus.

35.Find the frequencies of the two given tuning forks using resonating air column apparatus.(Velocity of sound in air = 330

36.Draw the lines of force around a short bar magnet placed with its North pole pointing the North in the earths magnetic field and locate null or neutral points, and find the magnetic moment of the given magnet.

37.Draw the lines of force around a short magnet placed with the south pole pointing the North in the earth’s magnetic field and locate null points and find pole strength of the magnet.

38.Verify Inverse square law using deflection magneto-meter.Take 3 readings.

39.Compare the magnetic moments of given two magnets using a deflection magnetometer in Tan - B position by i)equal distance method and compare results with null method.Take 2 observations in each case.

40.Compare the magnetic moments of given two magnets using a deflection magnetometer in Tan - A position by i)equal distance method and compare results with null method.Take 2 observations in each case.

41.Measure the current flowing through a circuit using a tangent galvanometer.Verify the results using an ammeter in the circuit.

42.Find the reduction factor of the tangent galvanometer using an ammeter in the circuit.Verify the result from theory.

SECTION - F

43.Draw R - Cos graph and hence verify the Ohm’s law.

44.Draw R - Cos graph and hence find the resistance of the tangent galvanometer and the battery.

45.Find the resistance and specific resistance of the given wire using a meter bridge.

46.Using mere bridge , find the resistance of given wires by connecting them in series and in parallel.

47.Compare the resistance’s of the given two wires using meter bridge.

48. Draw voltage - current ( V-I) characteristics of junction diode.

Scheme of valuation , Practical Examinations

2009-02-07T00:28:00.000-08:00

INTERMEDIATE PUBLIC EXAMINATIONS

PHYSICS PRACTICALS SCHEME OF PAPER VALUATION

Time : 3 Hours ________________________________________________Max Marks :30

S.NO		Marks
1.	Formula and Procedure	5 (2+3)
2.	Tabular form - Observations and Graph	8 (2+4+2)
3.	Calculations , Result and Units	6 (4+1+1)
4.	Precautions	2
5.	Viva - Voce	5
6.	Record book	4
	Total	30

Every student appearing for Intermediate practical examinations should know the scheme of valuation.While answering the question the student should keep in mind, that he should write the formula and procedure of the experiment.Then he should draw the Table to record the readings, after recording the readings , complete the calulations neately under the heading Calculations. After getting the result cleary write the value under the head Result and do not forget to write proper units where ever necessary.

Experiment :Vernier Calipers.

2009-01-30T05:58:00.001-08:00

Aim: To determine i) The volume of the given cylinder by measuring its length and diameter
ii ) The volume of the given sphere by measuring its diameter.

Apparatus : Vernier Calipers,Cylinder and sphere.

Description of Vernier Calipers: A Vernier calipers consists of mainly two parts i) A 2cm wide 15cm long rectangular metal strip .The left end bottom side of this strip consists of a fixed jaw 1 (A) and at the same end jaw 2(C) at the top of this strip. On the strip a scale (5)is graduated in Inches along the upper edge and another scale(4) is graduated in Centimeters along the lower edge. This is called Main Scale 'S' .
ii) A metal frame V called vernier slides over the Main Scale 'S' . At the bottom of this frame V a button 8(P) is attached,which helps to fix this vernier at any desired place on the main scale.This verier frame consists of jaw1 (B) at the bottom and a jaw 2(D) at the top .Two scales are graduated on this frame corresponding to two scales on the Main Scale 'S'. The two scales 6 and 7 on the vernier are called Vernier scale.Vernier scale consists of equal number of divisions. When we move vernier frame over the main scale, a thin strip (3) will be projected out.The projection will be exactly equal to the distance between Jaws 1(AB) i.e the thickness of the object between jaws.
The lower jaws 1,1(AB) are used to measure the thickness or external diameter of the tubes,cylinders or spheres.
The upper jaws 2,2 (CD) are used to measure the inner diameters of hallow bodies like tubes or holes.
The thin strip ( 3) is used to measure the depth of the objects like test tubes.

Theory : Principle of vernier calipers - N divisions on the vernier scale is equal to (N-1) divisions on the main scale.

N V.S.D = (N-1) M.S.D

1 V.S.D = M.S.D

Least count (L.C) of vernier calipers : Minimum length or thickness measurable with the vernier calipers is called its least count.

Least count (L.C) = 1 M.S.D - 1 V.S.D

L.C = 1 M.S.D - M.S.D

L.C = 1 M.S.D [ 1-]

L.C = =

Where S is the value of one Main scale division and N is the number of equal divisions on the vernier scale.

Procedure : First we have to determine the least count count of the given vernier calipers.

Total reading = M.S.R + ()

c) To determine the volume of the cylinder :Substituting the values of mean length (l ) of the cylinder and mean diameter ( r) of the cylinder which is already determined, in the formula V = .

d)To determine the diameter of the sphere : The given sphere is held firmly between jaws of the vernier calipers, in such a way the points where the jaws are in contact with sphere should be the two extremes of the chord of the cylinder.Post the values of the M.S.R and vernier coincidence (n) in the table . Take at least 5 readings, calculate the average of these readings which gives the mean diameter (d=2 r ) of the sphere.

e)To determine the volume of the sphere :Calculate the radius of the sphere r = d/2 .Substitute the value of mean radius (r) in the formula of the volume of the sphere V = .

Precautions to be taken while doing the experiment : 1) Take the M.S.R and vernier coincide every time without parallax error. 2)Record all the reading in same system preferably in C.G.S system. 3) Do not apply excess pressure on the body held between the jaws. 4) Check for the ZERO error.When the two jaws of the vernier are in contact,if the zero division of the main scale coincides with the zero of the vernier scale no ZERO error will be there.If not ZERO error will be there, apply correction.

Observations:

I) Least count of Vernier calipers :

a) Value of 1 Main scale division = 1 M.S.D = S = …….. cm,

b) Number of divisions on the vernier scale N= ……… cm,

Least count L.C = = ………. cm.

II) Volume of the Cylinder :

a)Length of the cylinder :

S.No	M.S.R acm	Vernier Coincidence (n)	Fraction b=n*L.C	Total Reading (a+b) cm
1.
2.
3.
4.
5.

Average length of the cylinder l = ……… cm.

b) Diameter of the cylinder :

a)Length of the cylinder :

S.No	M.S.R acm	Vernier Coincidence (n)	Fraction b=n*L.C	Total Reading (a+b) cm
1.
2.
3.
4.
5.

Average diameter of the cylinder d = 2r = …………. cm,

Mean radius of the cylinder r = d/2 = ………….. cm,

Volume of the cylinder V = .

III ) Volume of the sphere :

a) Diameter of the sphere :

S.No	M.S.R acm	Vernier Coincidence (n)	Fraction b=n*L.C	Total Reading (a+b) cm
1.
2.
3.
4.
5.

Average diameter of the sphere d = 2r = …………. cm,

Mean radius of the sphere r = d/2 = ………….. cm,

Volume of the sphere V = .

Result : 1. Volume of the given cylinder V= ………..

2.Volume of the given sphere V= ……….. .

Review Questions - Vernier calipers.

During practical examinations the examiner can shoot any question related to the experiment you are doing.Here I will try to answer few Frequently asked questions by examiner.

1Q: What is the advantage of vernier calipers over a regular scale graduated in millimeters?

Ans: We can measure up to a millimeter with regular scale which is graduated in millimeters, Where as with a vernier calipers with 10 equal divisions on the vernier scale we can measure up to 1/10 (0.1) mm accurately.

2Q:What is the principle of vernier ?

Ans: (N-1) main scale divisions = N divisions on vernier scale,

(N-1) M.S.D = N V.S.D is the principle of vernier.

3Q:What do you mean by least count of vernier calipers?

Ans: The difference of 1 M.S.D and 1 V.S.D is called least count of a vernier calipers. (or) The minimum

length which can be measured by a vernier calipers is called its least count.

4Q:What is the use of lower jaws of a vernier calipers?

Ans: The lower jaws or used to measure the thickness of object,outer diameters of tubes,spheres and cylinders.

5Q:What is the use of upper jaws?

Ans: The upper jaws of the vernier calipers are used to measure the inner diameters of rings,tubes and inner diameters of hallow cyliders , hallow spheres.

6Q:What is the use of the thin strip moving behind the main scale?

Ans: The strip is used to measure the depths of the tubes and level of the liquid inside tubes or jars.

7Q:Two different vernier calipers have different number of equal divisions on their vernier scales i) 10 equal divisions ii) 50 equal divisions . Which can measure more accurately.

Ans: The least count of the I vernier calipers = S/N = =0.1mm

The least count of the II vernier calipers = S/N = =0.02mm.

That is the II vernier calipers with 0.02mm of L.C can measure up to 0.02mm accurately.Hence the accuracy of II vernier calipers in more than I vernier calipers.

8Q:What is the ZERO error of a vernier calipers?

Ans:When two lower jaws of the vernier calipers are in contact, if the zero division of main scale does not coincide with the zeroth division of vernier scale, such vernier calipers will have zero error.

9Q: What is the formula of least count?

Ans: Least count L.C = .

10Q:What is the formula to calculate the volume of the cylinder?

Ans: Volume of the cylinder V = . , where r = radius of the cylinder and l = length of the cylinder.

11Q:What is the formula to calculate the volume of a Sphere?

Ans: Volume of the Sphere V = , where r = radius of the sphere.

12Q:What is the formula to calculate total reading with a vernier calipers?

Ans: Total reading = M.S.R + .

Practical Physics

Find the volume of the given rectangular glass plate using vernier calipers and screw gauge.

Contents :

Compare the radii of given three wires using Screw Gauge.

Screw Gauge

Find the volume of the Sphere - Vernier Calipers.

Find the volume of cylinder - Vernier calipers.

Practical Exams Question bank.

Scheme of valuation , Practical Examinations

Experiment :Vernier Calipers.