IMPORTANT QUESTIONS WITH ANSWERS
Q # 1. Define Physics? Describe its main areas of research.
Ans. Physics is the branch of science that deals with matter, energy and the relationship between
them. The study of physics involves laws of motion, the structure of space and time, the nature and
types of forces, the interaction between different particles, the interaction of radiation with matter etc.
Q # 2. What do you know about the natural philosophy?
Ans. Initially, the observations of man about the world around him give birth to the single discipline
of science, called natural philosophy.
Q # 3. Differentiate among the physical and biological sciences.
Physical Sciences Biological Sciences
i) Physical sciences deal with non-living things.
ii) Examples: Physics, Chemistry, Astronomy
i) Biological sciences deal with living things.
ii) Examples: Zoology, Botany etc.
Q # 4. Define the following branches of modern physics.
(i) Nuclear Physics (ii) Particle Physics (iii) Relativistic Mechanics (iv) Solid State Physics
Ans. (i) Nuclear Physics: The nuclear physics deals with the atomic nuclei.
(ii) Particle Physics: It deals with the ultimate particles with which the matter is
composed.
(iii) Relativistic Mechanics: It deals with motion of bodies which moves with very large
velocities (approaching that of light).
(iv) Solid State Physics: The solid state physics deals with structure and properties of matter.
Q # 5. Write down the significance of science and technology. Also describe the role of physics in the development of science and technology?
Ans. Modern tools of science and technology have brought all parts of world in close contact. The
information media and fast means of communications have made the world a global village. The
computer networks play pivotal role in the development of science and technology. The computer
networks are the products of chips developed from basic ideas of physics.
Q # 6. What do you know about physical quantities? Also describe their significance.
Ans. The quantities that can be measured and are used to describe the properties of matter are called
physical quantities.
Significance: The foundation of physics rest upon physical quantities in terms of which the laws of
physics are expressed.
Q # 7. Differentiate among the base and derived quantities.
ANS.BASE QUANTITIES
Q # 8. How the base quantities are measured?
Ans. The measurement of base quantity involves two steps:
(i) The choice of a standard.
(ii) The establishment of a procedure for comparing the quantity to be measure with standard.
Q # 9. What are the characteristics of an ideal standard?
Ans. An ideal standard has two principle characteristics.
(i) It is accessible
(ii) It is invariable
Q # 10. What do you know about international system of units? Describe its significance.
Ans. In 1960, an international committee agreed on a set of definitions and standards to describe the
physical quantities. The system that was established is called System International of units.
Significance: Due to simplicity and convenience with which the units in this system are amenable to
arithmetic manipulation, it is in universal use by the world’s scientific community.
Q # 11. Define following?
(i) Base Units (ii) Derived Units (iii) Supplementary Units (iv) Radian (v) Steradian
Ans. (i) Base Units: The units associated with the base quantities are called base units.
(ii) Derived Units: The units associated with the derived quantities are called derived units.
(iii) Supplementary Units: The General Conference on Weights and Measures has not yet
classified certain unit of SI under either base or derived units. These SI units are called
derived supplementary units. Radian and steradian are supplementary units.
(iv) Radian: The angle between two radii of a circle corresponding to the arc length of one
radius on its circumference is called radian.
(v) Steradian: The 3D angle subtended at the center of the sphere corresponding to the
surface area of one square radius is called steradian.
Q # 12. What do you mean by scientific notation? Describe the following numbers in scientific
notation.
(i) 134.7 (ii)0.0023 (iii)43.94*19
Ans. The standard form to represent numbers using power of ten is called scientific notation. In
scientific notation of any measurement, there should be only one non-zero digit at the left of the decimal point. The measurements expressed in scientific notation are as follows:
(i) The scientific notation of measurement 134.7 is 1.347 × 10
(ii) The scientific notation of measurement 0.0023 is 2.3 × 10
(iii) The scientific notation of measurement 43.94 × 10 is 4.394 × 10
Q # 13. Define error. Also describe possible causes of error.
Ans. The difference between the observed and calculated value of any measurement is called error.
The errors may occur due to following reasons.
Q # 14. What types of errors are possible in measuring the time period of pendulum by stop
watch? [BISE Sargodha 2008, 2009]
Ans. The possible errors that might occur are the personal error and systematic error. The personal
error occurs due to negligence or inexperience of a person, while the systematic error may be due to
the poor calibration of equipment or incorrect marking etc.
Q # 15. Differentiate among the random and systematic error.
Random Error
If the repeated measurements of a quantity
Systematic error refers to the effect that
Ans. In any measurement, the accurately known digits and the first doubtful digit are called the
significant figures. The uncertainty or accuracy in the value of a measured quantity is indicated by
significant figures.
Q # 1. Define Physics? Describe its main areas of research.
Ans. Physics is the branch of science that deals with matter, energy and the relationship between
them. The study of physics involves laws of motion, the structure of space and time, the nature and
types of forces, the interaction between different particles, the interaction of radiation with matter etc.
Q # 2. What do you know about the natural philosophy?
Ans. Initially, the observations of man about the world around him give birth to the single discipline
of science, called natural philosophy.
Q # 3. Differentiate among the physical and biological sciences.
Physical Sciences Biological Sciences
i) Physical sciences deal with non-living things.
ii) Examples: Physics, Chemistry, Astronomy
i) Biological sciences deal with living things.
ii) Examples: Zoology, Botany etc.
Q # 4. Define the following branches of modern physics.
(i) Nuclear Physics (ii) Particle Physics (iii) Relativistic Mechanics (iv) Solid State Physics
Ans. (i) Nuclear Physics: The nuclear physics deals with the atomic nuclei.
(ii) Particle Physics: It deals with the ultimate particles with which the matter is
composed.
(iii) Relativistic Mechanics: It deals with motion of bodies which moves with very large
velocities (approaching that of light).
(iv) Solid State Physics: The solid state physics deals with structure and properties of matter.
Q # 5. Write down the significance of science and technology. Also describe the role of physics in the development of science and technology?
Ans. Modern tools of science and technology have brought all parts of world in close contact. The
information media and fast means of communications have made the world a global village. The
computer networks play pivotal role in the development of science and technology. The computer
networks are the products of chips developed from basic ideas of physics.
Q # 6. What do you know about physical quantities? Also describe their significance.
Ans. The quantities that can be measured and are used to describe the properties of matter are called
physical quantities.
Significance: The foundation of physics rest upon physical quantities in terms of which the laws of
physics are expressed.
Q # 7. Differentiate among the base and derived quantities.
ANS.BASE QUANTITIES
(i) The base quantities are those physical
quantities in terms of which other physical
quantities are defined.
(ii) Examples: Mass, length, time
- Derived Quantities
(i) The quantities that are derived from the base
quantities are called derived quantities.
(ii) Examples: Velocity, acceleration, forceQ # 8. How the base quantities are measured?
Ans. The measurement of base quantity involves two steps:
(i) The choice of a standard.
(ii) The establishment of a procedure for comparing the quantity to be measure with standard.
Q # 9. What are the characteristics of an ideal standard?
Ans. An ideal standard has two principle characteristics.
(i) It is accessible
(ii) It is invariable
Q # 10. What do you know about international system of units? Describe its significance.
Ans. In 1960, an international committee agreed on a set of definitions and standards to describe the
physical quantities. The system that was established is called System International of units.
Significance: Due to simplicity and convenience with which the units in this system are amenable to
arithmetic manipulation, it is in universal use by the world’s scientific community.
Q # 11. Define following?
(i) Base Units (ii) Derived Units (iii) Supplementary Units (iv) Radian (v) Steradian
Ans. (i) Base Units: The units associated with the base quantities are called base units.
(ii) Derived Units: The units associated with the derived quantities are called derived units.
(iii) Supplementary Units: The General Conference on Weights and Measures has not yet
classified certain unit of SI under either base or derived units. These SI units are called
derived supplementary units. Radian and steradian are supplementary units.
(iv) Radian: The angle between two radii of a circle corresponding to the arc length of one
radius on its circumference is called radian.
(v) Steradian: The 3D angle subtended at the center of the sphere corresponding to the
surface area of one square radius is called steradian.
Q # 12. What do you mean by scientific notation? Describe the following numbers in scientific
notation.
(i) 134.7 (ii)0.0023 (iii)43.94*19
Ans. The standard form to represent numbers using power of ten is called scientific notation. In
scientific notation of any measurement, there should be only one non-zero digit at the left of the decimal point. The measurements expressed in scientific notation are as follows:
(i) The scientific notation of measurement 134.7 is 1.347 × 10
(ii) The scientific notation of measurement 0.0023 is 2.3 × 10
(iii) The scientific notation of measurement 43.94 × 10 is 4.394 × 10
Q # 13. Define error. Also describe possible causes of error.
Ans. The difference between the observed and calculated value of any measurement is called error.
The errors may occur due to following reasons.
(i) Negligence or inexperience of a person
(ii) The faulty apparatus
(iii) Inappropriate method or technique
watch? [BISE Sargodha 2008, 2009]
Ans. The possible errors that might occur are the personal error and systematic error. The personal
error occurs due to negligence or inexperience of a person, while the systematic error may be due to
the poor calibration of equipment or incorrect marking etc.
Q # 15. Differentiate among the random and systematic error.
Random Error
If the repeated measurements of a quantity
- give different values under same conditions,then the error is called random error.
- The random error occurs due to some
unknown causes - Repeating the measurement several times
and taking an average can reduce the effect
of random error.
Systematic error refers to the effect that
- influences all measurement of a particular
quantity equally. - It may occur due to zero error of the
instrument, poor calibration or incorrect
marking etc. - The systematic error can be reduced by
comparing the instrument with another
which is known to be more accurate.
Ans. In any measurement, the accurately known digits and the first doubtful digit are called the
significant figures. The uncertainty or accuracy in the value of a measured quantity is indicated by
significant figures.
0 comments:
Post a Comment