Practical Exams Question bank.

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.

Experiment :Vernier Calipers.

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.

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 = .

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 + .