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Question: 1
Define Screw gauge
Answer: 1
1-45A device used o measure a fraction of smallest scale division by rotatory motion of circular scale over it is known as screw gauge.
Question: 2
Write uses of Vernier Calliper
Answer: 2
2-45Vernier callipers is an instrument used o measure small lengh accurately up 0.1 mm or 0.01 cm, It can be used to measure the thickness, diameter or width of an object and the intenal, extenal diameter of hollow cylinder.
Question: 3
Define VErnier scale:
Answer: 3
3-45A vernier scale which has markings of some multiple of the markig on the main scale. The vernier scale usually has length of 9 mm and is divided eqally into 10 division The separation between two lines on vernier scale is 9/10 mm = 0.9 mm. Vernier scale contains jaw B on its left end.
Question: 4
What are prefixes ? Explain with examples.
Answer: 4
4-45Prefixes: A mechanism through which a very small or very large number is expressed in terms of power of 10 by giving a proper name to it is called prefixes.
Explanation: Prefixes are use before a standard unit to show how much larger or smaller the given physical quantity is a compared to the standard unit of that quantity.
Prefixes make standard form to be written even more easily. Large numbers are simply written is more convenient prefix with units.
Example: The thickness of a paper can be written conveniently is smaller uits of millimeter istead of meter.
Question: 5
Define Physics , How Physics play a cruicial role in science , technology and society,.
Answer: 5
5-45Physics: Physics is the branche of science that involves the sutdy of physicals universe. energym matter, and how they are related.
Explanation: The study of physics is to understand the world around us the world inside us and the world beyound us. physics covers a wide range of phenomena, from the smallest sub-atomic particles to the largest galaxies and unveirse.
Question: 6
What is standard form or scientific notation.?
Answer: 6
6-45Scientific Notation: Scientific Notation is a way of writing numbers that are to big or too small to be easily written in decimal form.
Explanation: A large or small number 'N' can be expressed in terms of a number 'M' Aand a power of 10 like N = m x 10n
Whee 'M'represents a number whose first digit is non-zero digit and 'n' represent the power of 10 which may be positive or negative.
Example: The mass ofmoon is approximately 70,000,000,000,000,000,000,kg.
Question: 7
What is Vernier Constant or Lest Count
Answer: 7
7-45Minimum length which can be measured accurately with the help of a vernier callipers is called vernier constant or least count of vernier callipers. The least coun of vernier callipers is calculated by
Least count =
smallest division on main scale/ Total no. of divisions on vernier scale.
If the smallest main scale division is 1 mm and vierneir scale division has 10 divisions on it then the least count is.
Least count= 1 mm/10
0.1 mm
= 0.01 cm
Question: 8
What are physical quantities? Distinguish between base and derived physical quantities.
Answer: 8
8-45Difference between base and derived physical quantities:
Base Quantities Derived Quantities.
Minimum numebr of physical The Physical quantities defied
quantities selected and their units in term of base quanties are
are define dand standardized called derived quantities.
scu that in terms of these
all o ther physical quantites
can be expressed are called base
quantities.
These are seven in number These are infinite,have
no fix number.
Example: Examples:
Length, mass, time,electric current Speed, area,volume
temperagture, amount of substance density, work and
and intensity of light. momentum etc.
Question: 9
What is Least count of Screw gauge.
Answer: 9
9-45The minimum length which can be measured accurately by a screw gauge is called least count of screw gauge. The least count of screw gauge is fond by dividing its pitch by the total number of circular scale division.
Least count= pitch of screw gauge/ Total no of division on circular scale.
Least Count = 0.5 mm/ 50
= 0.01 mm
= 0.001 cm.
Question: 10
What is vernier Calliper
Answer: 10
10-45Vernier Calliper: A device used to measure a fraction of smallest scal edivision by sliding another scale over it is called vernier calliper.
Question: 11
Define Main Scale
Answer: 11
11-45A main scale which has markings of usually of 1 mm each and it contains jaw A on its left end.
Question: 12
What is SI? Name SI base quantities and their units?
Answer: 12
12-45International System of units: In 1960 international confernece was held near Paris in France. IN this conference, it we decided to intrduce a system which could be used all over the world. It was given the name of system international. The international system of nit's is abbreviated as SI units In this system seven quantities were chosen as basic quantites. The units of these quanttities are defined and they are known a Bas Units. from which all other units are derived.
Question: 13
What are physical quantities? Dicuss its types.
Answer: 13
13-45PHYSICAL QUANTITIES: All those quantities whihc can be measured are calle dphysical quantities.
Example: Loength, mass, time density and temperature etc.
TYPES OF PHYSICLA QUANTITIES:
There are two types of physical quantitis which are givne below:
1- Base Physical Quantities
2- Derived physical quantities.
Question: 14
What is Vernier Callipers:
Answer: 14
14-45VERNIER CALLIPERS: A device used to measure a fraction of smallest scale division by sliding anothe acale over it is called vernier calipers.
Question: 15
Discuss the contribution o Muslim scientists in the development of Physics?
Answer: 15
15-45Scientists of the Islamic world contributed in the development . Few of the notable scientists are.
Question: 16
Write General Rules for significant Figures.
Answer: 16
16-451- Non-zero digits are alwyas significant . That is all the digits from 1 to 9 are significant, for example the number of significant figures in 47.73 is four.
2- Zero is between two significant figures are not significant.For example , the numebr of significant figures in 32.50063 is seven.
3- Zeros to the left of significant figures are not significant For example, the number of significant figures in 0.00467 is three.
Question: 17
What are measurig Instruments?
Answer: 17
17-45MEASURING INSTRUMENTS: Measuring instruments are devices to measure physical quantities.
Physicists use large numebrof measuring instruments. These range rom simple objets such as rulers and stopwatches to Atomic Force Microscope and Scanning Tunneling Electron microscope . All measuring instruments have some measruring limitations.
LEAST COUNT: Least count is the minimum value that can be measured on the scale of a measuring instrument.
Question: 18
What is meant by the significant figures of measurement?
Answer: 18
18-45Significant Figures: The number of accurately known figures and the first doubtful figure are known as significant figures.
Question: 19
What is system of units?
Answer: 19
19-45SYSTEM OF UNITS: A complete set of units for all physical quantities is called system of units.
There are several system of uits.
For example:
Meter Kilogrma second system
Foot pound second system.
But the system which is used internationally is system internatioal.
Question: 20
What is MAIN SCALE:
Answer: 20
20-45MAIN SCALE: A main scale which has markings of usually 1 mm each and it contains jaw A on its left end.
Question: 21
Uses of Screw Gauge.
Answer: 21
21-45ghe screw gauge is used to measure very short lengths such as the sthickenes sof metal sheet or diameter of a wire up to 0.01 mm or 0.001 cm.
Question: 22
Discuss the work of famous Pakistani Physicists?
Answer: 22
22-45Dr. Abdus Salam: He was born in Jhang in 1926. He was a Pakistani theoretical physicist. He shared teh 1979 Nobel Prize in physics with sheldon Glashow and Steven Weinberg for his contribution to the electroweak unification theoyr. He was the first Pakistani to reveive a Nobel Prize in Science.
Dr. Abdul Qadder Khan: He was born in Bhopal. India in 1939 . He is a Pakistani nuclear physicist and a metallurgical engineer, who foundd the uranium enrichement program for Pakistan's atomic bomb project. He dounded and established the Kahuta Research Laboratries in 1976, and severed as both its senior scientist and Director-General until he fretired in 2001.
Question: 23
What is Physics? Describe main branches of Physics.
Answer: 23
23-45Physics Physics is the branch of science which deals with the properties of matter, envery and their mutual relationship.
Brnchses of Physics:
Mechanics: The branch of physics which deals with the motion of material objects under the action of forces.
Example: Falling objects, friction, weithl spinning objects.
2- Heat and Thermodynamcis: The branch of physics which deals with the heat and temperature and their relation to energy. It also deals with the transformation of heat energy into othe rforms of energy.
Example: Melting and freezing processes, engines refrigerators.
3- Oscillations and Waves: The branch of Physics which deals with the study of to and fro motion and virious properties of waves.
Example: Mass-spring system, water waves, aound waves etc.
4- Optics: The branch of physics which deals with the nature of light, its propaggation, reflectionl refraction, dispersion and the wave properties of light.
Exmple: mirrors, leanses, telescopes, Eye.
5- Electricity and Magnetism: The branch of physics which deals with the study of static as well as moving charges and associated physical phenomena.
Exmple: Electricl charge, circuitry, magnets, electromagnets.
Agtomic and Nuclear Physics: The branch of Physics which deals with the structur eand properties of individual atoms and nuclei o an atom.
Exampe: X-rays, laswrs, nuclear reactor, MRI.CT scan,. PET Scan.
Question: 24
Write uses of Screw Gauge
Answer: 24
24-45The screw gauge is used to measure very short lengths such as the thickness f metal sheet or diamete of a wire up to 0.01 mm or 0.001 cm.
Question: 25
Describe the purpose of Scrw gauge.
Answer: 25
25-45A device used to measure of fraction of smalles scale division by rotagtory motionof circular scale over it is known as screw guage.
Question: 26
Write Zero Error of Screw Gauge.
Answer: 26
26-45Turn the thimble uitil the anvil and spindle meet. If the zero mark on ghe thimble scale does not lie directly opposite the datum line of the main scale, we say that there is zero error.
Question: 27
What is Zero correction:
Answer: 27
27-45ZERO CORRECTION: If the error is positive this value is subtracted from the actual reading. If the error is negative, the value is added to the actual reading.
Question: 28
Define NEGATIVE ZERO ERROR.
Answer: 28
28-45NEGATIVE ZERO ERROR: When the zero of the vernier scale is left of the zero of the main scale, such error is called negative zero efror.
Question: 29
What is Posiive Zero Error:
Answer: 29
29-45When the zero of the vernier scale remains right to the zero of the main scale, such error is called positive zero error.
Question: 30
Write Least Count of Screw Gauge.
Answer: 30
30-45The minimum length which can be measured accurately by a screw gauge is called least count of screw gauge. The least count of screw gauge is found by dividing its pitch by the totla numebr of circular scale dividions.
Least Count= pitch of screw gauge/ total number of divisions on circular scale.
Question: 31
Write Pitch of Screw gauge.
Answer: 31
31-45The distance travelled by the circular scale on linear scale in one rotation is called the pitch of screw gauge.
Question: 32
Wrie Positive Zero Error of Screw Gauge.
Answer: 32
32-45If the zero of the circular scale remains below the horizontal line then such zero error is called positive zero error.
Question: 33
What is VERNIER SCALE:
Answer: 33
33-45VERNIER SCALE: A vernier scale scale which has markings of some multiple of the markings on the main scale. The vernier scale usually has length of 9 mm and is divided equally into 10 divisions. The separation between two lines on vernier scale is 9/10 mm= 0.9 mm. Vernier scale contains jaw B on its left end.
Question: 34
Write Measurement With Vernier Callipers.
Answer: 34
34-451- First of all check the zero error of the vernier callipers.
2- Now place the object between the jaws of vernier callipers and tight them.
3- Nor note the reaing main scale. Let this reading be represented by "x|
4- Now add "x" and "y" which is measurement of the givne object.
Question: 35
What is Pitch of Screw Gauge.
Answer: 35
35-45The distance travelled by th ecircula scale on liner scale in one rotation is called the pith of screw gauge.
Question: 36
Define ZERO ERROR:
Answer: 36
36-45ZERO ERROR: On closing the jaws of the callipers, the zero of the vernier scale may or may not concide with the zero of the main scale. If their zero does not coincide, there is zero error in the instruments.
Question: 37
Adult hosefly is haing a mass of only about 0.0000214 kg . Expess this numebr is standard form/scientific notion.
Answer: 37
37-45Data :
Mass of housefly = 0.0000214 kg
Solution:
As we know that
N = m x 10 n
So,
0.0000214 kf - 2.4 z 10-5 kg
There fore ,mass of housefly in scientific notation is 2.14x10-5 kg.
Question: 38
Discuss the purpose, construction and working of measuring cylinde.
Answer: 38
38-45MEASURING CYLINDER: Measuring cylinder is a device with the help of which we can determine the volume of a liquid as well as volume of irregular solid body such as key.
CONSTRUCTION: It is made of transparent plastic or glass and it has a vertical scale in mililiter or cubic centimeter.
WORKING: Water is poured into a measuring cylinder unitl the cylinder is about half full. Note the volume of water.
Now an irregular shaped object is lowered gently into the cylinder such that it is immersed completwly and note the volume of water again. The final volume is the sum of volume of water and voume of the object.
The volume of the object is found by subtracting the first reading from the second.
Question: 39
What is stop watch? Discuss its types and their working?
Answer: 39
39-45STOP WATCH: It is a device which is used for measureing specific intervals of time There are two main types of stop watch.
1- Mechanicla or Analogue Stop Watch
2- Digital Stop Watch
Question: 40
What is Physical Blance?
Answer: 40
40-45PHYSICAL BALANCE: It is device which is used for measuring the mass of a body.
Explanation: Physical balance is a common balance where there are two pans and we measure weight of an object byputting it in one pan and a known weight in the other.
A Physical balance is a very sensitive common balance which can masure weight in miligram order. It is placed in a protectiv eglass case so tha teven dust and wind can not effect the accuracy of the instrument.
Question: 41
What is Physical Quantities.
Answer: 41
41-45In physics we study only those quantites which can be define dand measured, Quantities like length, mass, time, density, temperature can be measured therefore they are called physical quantities.
Question: 42
Write Netative Zero Error.
Answer: 42
42-45If the zero of the circular scale remains above the horizontal line of the linear scale then such zero error is called negative zero error.
Question: 43
Physics and biology are considered different branches of science, how phhsics links with biology.
Answer: 43
43-45Physics helps biology to great extent for example
1- Physics leads us to great invention like microscope, electron microscope, Computer Tomography , Ultrasonic Machines, X-rays etc.
2- Physics has invented concave and convex lenses which are widely used to correct short and long sightedness.
3- The movement of muscles and bones are studied and followed by the principles ofphysics
4- Physics has helped aslot to understand photosynthesis by describing the nature of lighit.
Question: 44
What are measurments important?
Answer: 44
44-45Measurement is one of the most basic concepts in science. Physics deals with physical quantities which can be measured. So, measuremtn provides a standard for everyday things and processes.
Example:
1- Without the ability to measure, it would b e difficult for scientists to conduct experiments.
2- Without measurements,there would be no concept of freezing point, boiling point and density etc.
3- Without measurments, patients are unable to take correct dose of medicines.
4- Without measuremnets, buying and selling of things are impossible.
5- It is also essential in farming, engineering, constrction, and manufacturing etc.
Question: 45
Write Measurment with screw gauge.
Answer: 45
45-451- First of all check the screw guage for zero error.
2- place the object between anvil and spidle and tight the sphere by rotating the thinble.
3- Now note the reading on linear scale and denote it by "x"
