Welcome to the fascinating world of electrostatics, a captivating unit in the realm of physics! In this comprehensive set of 10th-grade physics notes, we get into Unit 13: Electrostatics, where we explore the mesmerizing behavior of electric charges and their interactions. Understanding the principles of electrostatics is not only essential for acing your physics exams but also for comprehending the fundamental forces that govern our everyday lives. From the mysterious attraction and repulsion of charged particles to the intriguing concepts of electric fields and potential, these notes will equip you with the knowledge to unlock the secrets of static electricity and lay the foundation for advanced concepts in electromagnetism. So, let’s embark on this electrifying journey through the captivating realm of electrostatics.
10th Physics Unit 13 Long Question Notes
10th Physics Unit 13 MCQ’s Long Question Notes
- 10th Class Pak Study Textbook
- 9th and 10th Class General Science Textbook
- Chapter No. 9 Notes 10th Chemistry
- Biology 10th Class Past Papers
- English Past Papers of 10th Class
10th Physics Unit 13 Numerical Notes
10th Physics Unit 13 Short Question Notes
What property of substances causes them to attract or repel each other when rubbed?
Answer: Electric charges acquired during rubbing cause substances to attract or repel each other.
How can we produce electric charge in a neutral body?
Answer: Electric charge can be produced in a neutral body by rubbing it with another neutral body.
What are the two types of electric charges produced during rubbing?
Answer: The two types of electric charges produced during rubbing are positive charge and negative charge.
What happens when two like charges are brought near each other?
Answer: Like charges repel each other.
What happens when two unlike charges are brought near each other?
Answer: Unlike charges attract each other.
What is the sure test of charge on a body?
Answer: Repulsion between two bodies is the sure test of charge on a body.
What is electrostatic induction?
Answer: Electrostatic induction is the process where an insulated conductor develops positive charge at one end and negative charge at the other end in the presence of a charged body.
Is attraction a reliable test of charge on a body? Why or why not?
Answer: No, attraction is not a reliable test of charge on a body because it can also be the result of electrostatic induction, where the charges on the body remain zero.
In the list of materials, if two materials are rubbed together, which one will have a positive charge and which one will have a negative charge?
Answer: The material occurring first in the list will have a positive charge, and the material occurring next will have a negative charge.
What safety measures should be taken while dealing with static electricity?
Answer: Safety measures include grounding equipment to discharge static charges, using anti-static materials, avoiding flammable or explosive environments, and wearing appropriate protective clothing when handling sensitive electronic equipment.
What is an electroscope used for?
Answer: Detecting charges.
Describe the structure of a gold leaf electroscope.
Answer: It consists of a brass rod with a brass disk at the top and two thin leaves of gold foil hanging at the bottom.
How are charges able to move within the electroscope?
Answer: Charges can move freely from the disk to the leaves through the brass rod.
Why is an insulator used to hold the brass rod in place?
Answer: The insulator prevents the brass rod from conducting charges to external objects.
How is the electroscope protected from external electrical disturbances?
Answer: The leaves of the electroscope are protected by grounding the thin aluminum foil attached to the inside of the jar using a copper wire.
How can you detect the presence of charge on a body using the electroscope?
Answer: Bring the body near the disk of an uncharged electroscope. If the body is neutral, there will be no deflection of the leaves. But if the body is positively or negatively charged, the leaves of the electroscope will diverge.
Explain how an electroscope can be charged positively by electrostatic induction.
Answer: Bring a negatively charged body near the disk of the electroscope. Positive charge will appear on the disk, and negative charges will shift to the leaves. Connecting the disk to an earthed aluminum foil through a conducting wire allows the leaves’ charge to flow to the Earth. Removing the rod after breaking the Earth connection leaves the electroscope with positive charge.
How can an electroscope be charged negatively?
Answer: An electroscope can be charged negatively by bringing a positively charged rod near the disk and following the same process as described for charging positively.
How can you identify the type of charge on a body using the electroscope?
Answer: Charge the electroscope positively or negatively and then bring the charged body near the disk. If the divergence of the leaves increases, the body carries the same type of charge as the electroscope. If the divergence decreases, the body has the opposite charge.
How can an electroscope distinguish between conductors and insulators?
Touch the disk of a charged electroscope with material under test. If the leaves collapse from their diverged position, the body would be a good conductor. If there is no change in the divergence of the leaves, it will show that the body under test is an insulator.
What does Coulomb’s law state?
Answer: Coulomb’s law states that the force of attraction or repulsion between two point charges is directly proportional to the product of the magnitudes of the charges and inversely proportional to the square of the distance between them.
What are the variables involved in Coulomb’s law equation?
Answer: The variables involved are: F (force between the charges), q1 and q2 (magnitudes of the two charges), r (distance between the charges), and k (the constant of proportionality).
How is the force affected when the magnitude of the charges is increased?
Answer: The force between the charges increases proportionally to the increase in the magnitudes of the charges.
How is the force affected when the distance between the charges is increased?
Answer: The force between the charges decreases inversely proportional to the square of the distance between them. As the distance increases, the force decreases.
What is the SI unit of charge used in Coulomb’s law?
Answer: The SI unit of charge is the coulomb (C).
What is the value of the constant of proportionality (k) in Coulomb’s law if the medium between the charges is air?
Answer: The value of k in SI units will be 9 × 10^9 N m^2/C^2.
What are the units of electric field intensity?
Answer: The units of electric field intensity are newton per coulomb (N/C).
How is electric field intensity defined?
Answer: Electric field intensity at a point in space is the force experienced by a unit positive charge placed at that point.
What are electric field lines?
Answer: Electric field lines are imaginary lines used to represent the direction and strength of an electric field. They extend from positive charges to negative charges and their spacing indicates the strength of the electric field.
In an electric field, which direction do electric field lines point?
Answer: Electric field lines point away from positive charges and towards negative charges.
What is electric potential at a point in an electric field defined as?
Answer: Electric potential at a point in an electric field is equal to the amount of work done in bringing a unit positive charge from infinity to that point.
How is electric potential (V) related to the work done (W) in moving a positive charge (q) to a certain point in the electric field?
Answer: The electric potential (V) at a certain point is given by V = W/q.
What is the SI unit of electric potential?
Answer: The SI unit of electric potential is volt (V), which is equal to J C^-1 (joule per coulomb).
How is potential difference between two points defined?
Answer: Potential difference between two points is defined as the energy supplied by a unit charge as it moves from one point to the other in the direction of the electric field.
How is potential energy related to the potential difference between two points for a positive charge?
Answer: The potential energy of a positive charge at two points (A and B) with potentials V_A and V_B is given by q(V_A – V_B), where q is the charge.
What is a capacitor, and what does it do?
Answer: A capacitor is a device used to store electric charge. It consists of two parallel metal plates separated by a small distance, with a dielectric material between them.
What is capacitance, and how is it defined?
Answer: Capacitance (C) is the ability of a capacitor to store charge. It is defined as the ratio of charge (Q) stored on the plates to the potential difference (V) across the plates: C = Q/V.
What is the SI unit of capacitance, and can you give some smaller units used in practice?
Answer: The SI unit of capacitance is farad (F). Smaller units used in practice are microfarad (μF), nanofarad (nF), and picofarad (pF).
What are the characteristics of capacitors in parallel?
Answer: In parallel combination, each capacitor has the same potential difference across it, but different charges due to different capacitances. The total charge supplied by the battery is divided among the capacitors.
How can we replace a parallel combination of capacitors with one equivalent capacitor?
Answer: The equivalent capacitance of ‘n’ capacitors in parallel is given by Ceq = C1 + C2 + C3 + … + Cn.
Is the equivalent capacitance of parallel capacitors larger or smaller than the capacitance of any individual capacitor in the combination?
Answer: The equivalent capacitance of parallel capacitors is greater than any of the individual capacitances.
What are the characteristics of capacitors in series?
Answer: In series combination, each capacitor has the same charge across it, but different potential differences due to different capacitances. The total voltage of the battery is divided among the capacitors.
How can we replace a series combination of capacitors with one equivalent capacitor?
Answer: The equivalent capacitance of ‘n’ capacitors in series is given by 1/Ceq = 1/C1 + 1/C2 + 1/C3 + … + 1/Cn.
What are some examples of fixed capacitors?
Answer: Paper capacitor and mica capacitor are examples of fixed capacitors.
What is the dielectric used in a paper capacitor?
Answer: Oiled or greased paper or a thin plastic sheet is used as the dielectric in a paper capacitor.
How can the capacitance be increased in mica capacitors?
Answer: In mica capacitors, to increase the capacitance, a large number of plates can be piled up with layers of mica in between, and alternative plates are connected to each other.
What is an electrolytic capacitor used for?
Answer: An electrolytic capacitor is used to store a large amount of charge at relatively low voltages. It consists of a metal foil in contact with an electrolyte, and the thin layer of metal oxide formed on the foil serves as the dielectric.
What are some examples of electrical appliances that use capacitors for their smooth working?
Answer: Table fans, ceiling fans, exhaust fans, fan motors in air conditioners, coolers, washing machines, and air conditioners.
How are capacitors used in electronic circuits of computers?
Answer: Capacitors are used in filter circuits that tune radios to particular frequencies.
What type of capacitor is generally considered superior and suitable for vast ranges of applications?
Answer: Ceramic capacitors are generally considered superior and can be used in vast ranges of applications.
What is the purpose of an electrostatic air cleaner in homes?
Answer: An electrostatic air cleaner is used to remove contaminants from the air by attracting positively charged particles to a negatively charged mesh.
How do automobile manufacturers use static electricity in the painting process?
Answer: Automobile manufacturers use static electricity to evenly distribute and stick paint particles to the car’s body, resulting in an effective and economical way of painting automobiles on a large scale.
How is lightning caused, and what is used to prevent lightning damage to tall buildings?
Answer: Lightning is caused by a large quantity of electric charge building up in heavy thunderclouds. Lightning conductors are used to provide a steady discharge path for the charge to flow from the top of the building to the Earth, minimizing the chances of lightning damage.
What are some hazards of static electricity, especially in relation to fires and explosions?
Answer: Static electricity can cause fires and explosions when there is excessive buildup of electric charges due to friction. For example, sparks produced during fuel pumping or handling can ignite petrol vapour, leading to a serious explosion.