Matric Part 1/9th Class Physics Chapter 1 Long Question With Answer for Unit 1 Physical Quantities and Measurement

Question # 1

Write a note on Waves as carriers of Energy?

Ans 1: Waves as carriers of Energy: Energy can be transferred from one place to another through waves. Example: When we shake the stretched string up and down, we provide our muscular energy to the string. As a result, a set of wave can be seen travelling across the string. The vibrating force from the hand disturbs the particles of string and sets them in motion. These particles then transfer their energy to the adjacent particles in the string. Energy is thus transferred from one place of the medium to other. Dependence: The amount of energy carried by the wave depends on the distance of the stretched string from its rest position. That is the energy in a wave depends on the wave amplitude of wave. If amplitude and frequency are greater than more energy will be transfer. Example: If we shake the string faster, we give more energy per second to produce wave of higher frequency, and wave delivers more energy per second to the particles of the string as it moves forward. Energy. Transfer in Water: Water waves also transfer energy from one place to another. Example: If we drop a stone into pond of water. Water waves will be produce on the surface of water and will travel outward. Now if we place a cork at some distance from the falling stone. When waves reacts the cork, it will move up and down along with the motion of the water particles by getting energy from the wave. This shows that water waves like other waves transfer energy from one place to another without transferring in matter.

Question # 2

What is meant by Vernier callipers? Write its construction.

Ans 1: Vernier Callipers: A vernier callipers consist of two jaws. One is a fixed jaw with main scale attached to it. Main scale has centimeter and millimeter marks on it the other jaw is a moveable jaw, it has a vernier scale having 10 divisions over it such that each of its divisions is 0.9mm.The difference between one small division on main scale division and one vernier scale division is 0.1mm. It is called least count of the vernier callipers. Least count of =Smallest reading on main scale /no. Of decision on vernier scale Vernier Callipers LC = 1mm/10divisions = 0.1mm LC = 0.1mm = 0.01cm Zero Error and Zero Correction: First of all find the zero error. To find the zero error close the jaws of Vernie, callipers gently.Zero error will exist if zero line of the vernier scale is not coinciding with the zero of main scale Knowing the zero error , necessary correction can be made to find the correct measurement is called zero correction. Taking a Reading on Vernier Callipers: Find the diameter of a solid cylinder using vernier Callipers.Close the jaws till they press the opposite sides of the object gently. Note the complete divisions of main scale past the vernier scale zero in a tabular form. Next find the vernier scale division that is coinciding with any division on the main scale. multiply it by least count of vernier Callipers and add it in the main scale reading. This is equal to the diameter of the solid cylinder. Add zero correction (Z.C) to get correct measurement Repeat the above procedure and record at least three observations with the solid cylinder displaced or rotated each time

Question # 3

Define Physical quantities. Also write its types.

Ans 1: Physical Quantities: All measurable quantities are called physical quantities such temperature. A physical quantity possesses at least two characteristics in common. One is its numerical magnitude and the other is the unit in which it is measured. Example: If the length of a student is 104 cm then 104 is its numerical magnitude and centimeter is the unit of measurement. Types of Physical Quantities: Physical quantities are divided into base quantities and derived quantities 1- Base Quantities: There are seven physical quantities which form the foundation for other physical quantities, These physical quantities are called the base quantities. These are length, mass, time, electric current. Temperature, intensity of light and the amount of a substance. 2- Derived Quantities: Those physical quantities which are expressed in terms of base quantities are called the derived quantities. These include area, volume. speed, force, work, electric charge, electric potential etc.

Question # 4

Define scientific notation. describe it with examples

Ans 1: Scientific Notation; In scientific notation a number is expressed as some power of ten multiplied by a number between 1 and 10. A simple but scientific way to write large or small numbers is to express them in some power of ten.
The Moon is 3.84*10m. This form of expressing a number is called the standard form or scientific notation. This saves writing down or interpreting a large numbers of zeros
Ans 2: Standard Form; Number that has on e non zero digit before the decimal preferable to taken as standard

Question # 5

Describe the working of vernier caliper

Ans 1: Zero Error: The defect present in any instrument is called its zero error. TO find zero error, close the jaws of vernier caliper gently. If zero line of the vernier scale coincides with the zero of the main scale then zero error is zero.
Ans 2: Positive zero error: Zero error will be positive if zero line of vernier scales on the right side of the zero of the main scale
Ans 3: Negative zero error: If the zero line of vernier scale is on the left side of zero of the main cale so it is negative zero error
Ans 4: Zero correction: Knowing zero error , necessary correction can be made to find the corrected measurement such correction is called zero correction of the instrument OR the inverse of zero error is called zero correction.
Note : Zero correction will be positive or negative
Ans 5: Taking a reading on vernier caliper: let us find the dia.
meter of a solid cylinder using verinier caliper . Place the solid cylinder between jaws of the vernier caliper. Close the jaws til they press the oppostie side of the object gently. Note the complete division o main scale past the vernier scale zero. Now find vernier scale division that is coinciding with any division on the main scale . Multiply it by least count of vernicer caliper and add it in the main scale reading. This is equal to the diameter of the soild cylinder. Add zero correction to gert correct measurement. Repeat the above procedure and record at least three observations with the solid displaced or rotated each time.

Question # 6

Define physics and explain its branches

Ans 1: Physics: the branch of science which deals with the study of matter, energy and their mututal relationship is called physics

Branches of physics
Mechanics: The branch of physics which deals with the study of matter, energy and their mutual relationship is called physics
Ans 2: Heat: The branch of physics which deals with the nature of heat, modes of transfer and effects of heat is called heat

Sound: The branch of physics which deals with the study of physical aspects of sound wave, their production, properties and applications is called sound
Ans 3: Light: The branch of physics which deals with the study of physical aspects of lights ,its properties, working and use o optical instruments is called light

Electricity and magnetism: The branch of physics which deals with the study of charges at rest and in motion, their effects and their relationship with magnetism is called electricity and magnetism
Ans 4: Atomic physics: The branch of physics which deals with the study of structure and properties of atoms is called atomic physics

Nuclear physics: The branch of physics which deals with the study of properties and behavior of nuclei and their particles within nuclei is called nuclear physics
Ans 5: plasma: physics : The branch of physics which deals with the study of production, properties of ionic state of matter the fourth state of matter , is called plasma physics .

Geo physics: The branch of physics which deals with the study of internal structure of the earth is called geophysics

Question # 7

What is screw gauge. How a screw gauge is used to measure diameter of thin wire

Ans 1: Definition: An instrument which can measure length correct up to 0.01 mm or 0.001 cm is called a screw gauge

Micrometer screw gauge: An instrument which can measure length correct up to 10th part of millimeter is called micro meter screw gauge
Ans 2: Construction: A simple screw gauge consists of a U shaped metal frame with a metal stud at its on end . A hollow cylinder has a millimeter scale over it along a line called index line parallel to its axis. The hollow cylinder acts as a nut. It is fixed at the end of U shaped frame opposite to the stud. A thimble has a threaded spindle inside it.
Ans 3: pitch of screw gauge: The distance moved by spindle along index line as the thimble complete on rotation is called pitch of screw gauge i.e.1mm.spindle has 100 divisions around its one end. It is the circular scale of the screw gauge. As thimble completes one rotation, 100 pass the index line and the thimble moves 1 mm along the main scale
Ans 4: Least count of the screw gauge: Least count of a screw gauge can also be found by dividing pitch of screw gauge on number of divisions on circular scale i.e. 0.01mm or 0.001 cm
Least count = Pitch of screw gauge/no .of divisions on circular scale
Ans 5: Zero correction: Knowing zero error, necessary correction can be made to fine the correction such correction is called zero correction of the instrument. OR
The inverse of zero error is called zero correction.
Note: zero correction will be positive or negative

Question # 8

What is the most accurate balance . Explain with examples

Ans 1: The mass of one rupee con is done using different balances as given below
Ans 2: Beam balance: Let the balance measures coin's mass=3.2g
a sensitive beam balance may be able to detect a changes as small as of 0.1g or 100mg
Ans 3: Physical balance: let the balance measure coin's mass=3.24g least count of the physical balance may be as small as 0.01g or 10 mg. Therefore, its measurement would be more precise than a sensitive beam balance.
Ans 4: Electronic balance: Let the balance measure coin's mass=3.247g least count of an electronic balance is 0.01g or 1mg. Therefore, its measurement would be more precise than a sensitive physical balance
Ans 5: Conclusion: Thus electronic balance is the most sensitive balance in the above balances

Question # 9

Write note on significant figure

Ans 1: Significant figure: All the accurately known digits and the first doubtful digit in as expression are called significant figures. It reflects the precision of measure value of a physical quantity
Explanation: The value of a physical quantity is expressed by a number, along with suitable units. The accuracy in the measurement of a physical quantity depends upon
The quality of the measuring instrument
The skills of the observer
The number of observation made
The improvement in the quality of measurement can be made by using better measuring instrument, the more is value of precision more significant figure means greater precision
Ans 2: Rules of significant figure: The follow rules are helpful in identifying significant figure
Non zero digits are always significant
Zeros between two significant figures are also significant
Final or ending zeros on the right in decimal fraction are significant
Zeros written on the left side of the decimal point for the purpose of spacing the decimal point are not significant
In whole number s that end in one or more zeros without a decimal point these zeros may or may not be significant. In such case, express the quantity using scientific notation to find the significant zeros

Question # 10

Define science and describe how science was divided into various branches

Ans 1: Science :The knowledge gained through observations and experiments is called science .The wor science is derived from the Latin word "scientia", which means knowledge. Science was divided into various branches initially as described below;
Ans 2: Natural Philosophy: Not until eighteen century is known as natural philosophy. Later on as knowledge increased natural philosophy we divided into two branches.
biological sciences , physical sciences
Ans 3: Biological sciences: The branch of natural philosophy which deals with the study of liviing things is called biological sciences
Ans 4: physical sciences: The branch of natural philosophy which deals with the study of non-living things is called physical sciences. Physical sciences were divided into five distinct disciplines
physics, chemistry , geology , astronomy , meteorology

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Matric Part 1/9th Class Physics Chapter 1 Long Question With Answer for Unit 1 Physical Quantities and Measurement

9th Class English Medium Subjects

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Online Long Questions For Chapter 1 "9th Class Physics Chapter 1 Long Question Preparation "

Physics (New Book) - 9th Class Physics Chapter 1 Long Question Preparation

Write a note on Waves as carriers of Energy?

What is meant by Vernier callipers? Write its construction.

Define Physical quantities. Also write its types.

Define scientific notation. describe it with examples

Describe the working of vernier caliper

Define physics and explain its branches

What is screw gauge. How a screw gauge is used to measure diameter of thin wire

What is the most accurate balance . Explain with examples

Write note on significant figure

Define science and describe how science was divided into various branches

Prepare Complete Set Wise Questions For Chapter 1 "9th Class Physics Chapter 1 Long Question Preparation "

Set 1

Set 2

9th Class Physics Chapter 1 Long Question Preparation - Set 1

Write a note on Waves as carriers of Energy?

What is meant by Vernier callipers? Write its construction.

Define Physical quantities. Also write its types.

Define scientific notation. describe it with examples

Describe the working of vernier caliper

Define physics and explain its branches

What is screw gauge. How a screw gauge is used to measure diameter of thin wire

What is the most accurate balance . Explain with examples

Write note on significant figure

Define science and describe how science was divided into various branches

9th Class Physics Chapter 1 Long Question Preparation - Set 2

Your hair grow at the rate of 1mm per day . Find their growth rate in nms^-1

Define physics and explain its branches

What is screw gauge. How a screw gauge is used to measure diameter of thin wire

write a note on stopwatch and its types

Define scientific notation. describe it with examples

Define science and describe how science was divided into various branches

What are prefixes, explain it with examples

What are the significant figures in the following measurements?

Explain the construction and use of meter rule and measuring tape.

What is the most accurate balance . Explain with examples

9th class Physics Chapter 1 Long Q's (English Medium)