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

Question # 1

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 # 2

Give construction and use of vernier calipers

Ans 1: Definition: an accuracy greater than 1mm can be obtained by using instruments such as vernier caliper s.
OR
an instrument which can measure length correct up to 0.1 mm is called vernier caliper.
Ans 2: Construction: vernier caliper consists of two jaws. one is a fixed jaw, with main scale attached to it. Main scale has centimeter and milimeter marks on it. The other jaws is a moveable jaw. It has vernier scale having 10 divisions over it. Such that each of its division is 0.9 mm
Ans 3: Pitch: The distance between two small divisions on main scale of vernier calipers is called pitch of vernier caliper
Ans 4: Least count: The difference between one small division on main scale division and one vernier division is 0.1m is called least count of the vernier caliper . Its is also called as vernier constant. Such that 1mm - 0.9mm
0.1mm=0.01cm
Ans 5: Formula: least count of vernier calipers
=smallest reading on main scale/no. of divisions on vernier scale=1mm/10=0.1mm=0.01cm

Conclusion: This is the minimum length which can measure accurately with the help of vernier caliper

Question # 3

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 # 4

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 # 5

What is measuring cylinder. Explain it

Ans 1: Measuring cylinder: A measuring cylinder is a graduated glass cylinder used to measure the volume of liquid and also to fine the volume of an irregular shaped solid object
Ans 2: Construction; It is a glass or transparent plastic cylinder. it has a scale along its length that indicates the volume in milliliter. Measuring cylinders have different capacities from 100ml to 2500ml
use: it is used to measure volume of liquid or powdered substance. It is also used to dine volume of irregular shaped solid insoluble in liquid by displacement method
Ans 3: How to use measuring cylinder: Take a measuring cylinder, place it vertically on table. pour some water into it .Note that the surface of water will be curved. Meniscus of most liquids curves downward while meniscus of mercury curves upward. Correct method to note level of liquid in cylinder is to keep eye at same level as the meniscus of liquid. It is incorrect to keep eye above or below the liquid level.
When eye is above liquid level meniscus appears higher on scale. When eye is below liquid level, the meniscus appears lower than actual height of liquid.

Question # 6

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 # 7

A Chocolate wrapper is 6.7 cm long and 5.4cm wide. Calculate its area upto reasonable number of significant figures.

Ans 1: Given Data: Length = 6.7cm Width = 5.4cm Area = ? Solution: Area = length x width putting the values = 6.7 x 5.4 = 36.18cm² = 36.2 cm²

Question # 8

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 # 9

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 # 10

What is the importance of physics in our daily life

Ans 1: Law and principle of physics help us to understand nature
The rapid progress in science during the recent years has become possible due to discoveries and inventions in the field of physics. The technologies are the applications of scientific principles. Most of the technologies of our modern society throughout the world are related to physics. For example, car is made on the principles of mechanics and a refrigerator is based on principles of thermodynamics. In or daily lifer there are lots of applications of physics . For example in electrical appliances (air conditioners, washing machine),means of transport( cars, aero-planes ), means of communication (radio, T.V, Telephone) 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

Define science and describe how science was divided into various branches

Give construction and use of vernier calipers

What is the most accurate balance . Explain with examples

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

What is measuring cylinder. Explain it

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

A Chocolate wrapper is 6.7 cm long and 5.4cm wide. Calculate its area upto reasonable number of significant figures.

Define physics and explain its branches.

Write a note on mass measuring instruments

What is the importance of physics in our daily life

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

Define science and describe how science was divided into various branches

Give construction and use of vernier calipers

What is the most accurate balance . Explain with examples

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

What is measuring cylinder. Explain it

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

A Chocolate wrapper is 6.7 cm long and 5.4cm wide. Calculate its area upto reasonable number of significant figures.

Define physics and explain its branches.

Write a note on mass measuring instruments

What is the importance of physics in our daily life

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

What are the significant figures in the following measurements?

Write a note on mass measuring instruments

Define physics and explain its branches.

A Chocolate wrapper is 6.7 cm long and 5.4cm wide. Calculate its area upto reasonable number of significant figures.

Define science and describe how science was divided into various branches

What is the importance of physics in our daily life

write a note on stopwatch and its types

Write note on significant figure

What is the most accurate balance . Explain with examples

Define Physical quantities. Also write its types.

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

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