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

Question # 1

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 # 2

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

Ans 1: Solution: Rate of growth = 1mm per day =1mm/day =1x10^-3m/24x60x60s = 0.0000000115ms^-1 = 11.57 x10^-9 ms^-1 = 11.57 nms^-1

Question # 3

What are prefixes, explain it with examples

Ans 1: Prefixes; The words or letters added before a unit and stand for multiples or sub multiples of that unit are known as prefixes
Examples; kilo, mega, nano, micro etc.
Note ; The pre fixes are useful to express very large or small quantities.
double pre fixes are note used for examples no pre fix is used with kilogramme

Question # 4

Define physics and explain its branches.

Ans 1: Physics: Physics is a branch of science that deals with matter, energy and their relationship. Branches of Physics: Following ate branches of physics: 1- Machanics: It is the study of motion of objects, its causes and effects. 2- Heat: It deals with the nature of heat , modes of transfer and effects of heat 3- Sound: It deals with the physical aspects of sound waves , their production, properties and applications. 4- Light : It is the study of the physical aspects of light, its properties, working and use of optical instruments. 5- Electricity and Magnetism: It is the study of the charges at rest and in motion their effects and their relationship with magnetism. 6- Atomic Physics: it is the study of the structure and properties of atom 7- Nuclear Physics: It deals with the properties and behavior of nuclei and the particle within the nuclei: 8- Plasma Physics: It is the study of production, properties of the ionic state of matter 9- GeoPhysics It is the study of the internal structure of the Earth.

Question # 5

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 # 6

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 # 7

Write a note on mass measuring instruments

Ans 1: Introduction: Pots were used to measure grain in various part of the world in the ancient time . However, balances were also in use by Greeks and Romans.
Ans 2: beam balance: Beam balances are stil in use at may places . In a beam balance, the unknown mass is placed in one pan . It is balanced by putting known masses in the other pan.
Today people use many types of mechanical and electronic balances. you might have seen electronic balances in sweet and grocery shops. There are more precise than beam balances and are easy to handle.
Ans 3: Physical Balance: a physical balance is used in the laboratory to measure the mass of various objects by comparison
Construction: It consists of a beam resting at the centre on a fulcrum. The beam carries scale pans over the hooks on either side. unknown mass is placed on the left pan. Find some suitable standard masses that cause the pointer to reman at zero on raising the beam
Ans 4: Lever Balance : A lever balance consists of a system of levers. When lever is lifted placing the object in one pan and standard masses on the other pan, the pointer of the lever system moves. The pointer is brought to zero by varying standard mases. LC of lever balance is 0.01g ror 10mg
Ans 5: Electronic balance: Electronic balance comes in various ranges; milligram range, gram ranges and kilogram ranges. Before measuring the mass of a body, it is switched on and its reading is set to zero. Next place the object to the weighed. The reading on the balance gives you the mass of the body placed over it.

Question # 8

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

Question # 9

Define unit and what is international system of units

Ans 1: Unit: A standard quantity needed for measuring unknown quantities is called unit.
Example: Standard unit for measurement of mass is kilogram(kg), For length is meter(m) and for time is seconds(s)
Ans 2: System of units: A set of base and derived units is called system of units
International system of units: A world wide acceptable system of measurements is called international system of units. It is commonly reffered as S.I.
It was adopted in 11th General conference on weight and measures held in 1960 in Paris
Ans 3: Types: There are two types of units
Base units, Derived units
Ans 4: Base units: The units that describe table quantities are called base units .
Following table shows the S.I units of base quantities and their symbols
Name: Length, Mass, Time, Electric current, Intensity of light, Temperature, Amount of substance Meter, kilogram, Second, Ampere, Candela, kelvin, Mole
Ans 5: Derived Units: Units used to measure derived quantities are called derived units.
Derived units are defined in terms of base units and are obtained by multiplying or dividing one or more base units with each other. The units of area(meter) and the unit of volume(meter) are based on the unit of length, which is meter. Thus the unit of length is the base unit while the unit of area and volume are derived units. speed is defined as distance covered in unit time ;therefore its unit is meter per second. In the same way the unit of density, force, pressure, power etc. can be derived using one or more base quantities. Some derived units are as follow
Name; Speed , acceleration , volume ,force , pressure, density, charge, meter per second, meter per second per second, cubic meter, newton , pascal . kilogram per cubic meter and coulomb

Question # 10

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.

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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

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

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

What are prefixes, explain it with examples

Define physics and explain its branches.

What is the most accurate balance . Explain with examples

Write a note on Waves as carriers of Energy?

Write a note on mass measuring instruments

Define science and describe how science was divided into various branches

Define unit and what is international system of units

Define Physical quantities. Also write its types.

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

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

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

What are prefixes, explain it with examples

Define physics and explain its branches.

What is the most accurate balance . Explain with examples

Write a note on Waves as carriers of Energy?

Write a note on mass measuring instruments

Define science and describe how science was divided into various branches

Define unit and what is international system of units

Define Physical quantities. Also write its types.

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

What are the significant figures in the following measurements?

Describe the working of vernier caliper

Define physical quantities and explain its types

Define Physical quantities. Also write its types.

Give construction and use of vernier calipers

What is the importance of physics in our daily life

What is the most accurate balance . Explain with examples

What are prefixes, explain it with examples

Write note on significant figure

What is meant by Vernier callipers? Write its construction.

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

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