Electrostatics MCQs

What is Electrostatics?

Electrostatics is a fundamental chapter in Physics that explores the study of electric charges at rest and the forces and fields associated with them. This chapter introduces students to the basic concepts of electric charge, electric force, electric field, and electric potential. The unit covers Coulomb’s law, which describes the force between two charges, the concept of electric field lines, and the principle of superposition. Students also learn about capacitors, dielectrics, and the applications of electrostatics in various technologies.

Key Topics in Electrostatics:

Electric Charge: Understanding the nature and properties of electric charges, including conductors and insulators.
Coulomb’s Law: Exploring the mathematical relationship between the force exerted by one charge on another and their separation distance.
Electric Field: Analyzing the concept of the electric field, field lines, and the forces experienced by charges in an electric field.
Electric Potential: Learning about electric potential energy, potential difference, and the concept of voltage.
Capacitance: Studying capacitors, their ability to store charge, and the role of dielectrics in altering capacitance.
Applications of Electrostatics: Exploring practical applications and technologies that utilize electrostatic principles, such as electrostatic precipitators and capacitors in electronic circuits.

Benefits of Studying Electrostatics:

Fundamental Understanding: Provides a crucial foundation for studying electric circuits, electromagnetism, and more advanced topics in Physics.
Practical Applications: Equips students with knowledge applicable to various technologies and industries, including electronics, energy storage, and environmental control.
Academic and Career Preparation: Prepares students for further studies and careers in fields such as electrical engineering, physics, and materials science.

This chapter is essential for students to develop a solid understanding of electric forces and fields, which are foundational concepts in Physics. Whether preparing for exams or pursuing a career in science and technology, mastering Electrostatics is key to academic and professional success.

What is the SI unit of electric charge?
- a) Ampere
- b) Volt
- c) Coulomb
- d) Ohm
  Answer: c) Coulomb
The charge of an electron is:
- a) +1.6 × 10⁻¹⁹ C
- b) -1.6 × 10⁻¹⁹ C
- c) +1.6 × 10⁻¹⁸ C
- d) -1.6 × 10⁻¹⁸ C
  Answer: b) -1.6 × 10⁻¹⁹ C
Coulomb’s law describes the force between:
- a) Two magnetic poles
- b) Two electric charges
- c) Two currents
- d) A charge and a magnetic pole
  Answer: b) Two electric charges
According to Coulomb’s law, the force between two charges is inversely proportional to:
- a) The square of the distance between them
- b) The distance between them
- c) The product of the charges
- d) The sum of the charges
  Answer: a) The square of the distance between them
The electric field is defined as:
- a) Force per unit mass
- b) Force per unit charge
- c) Voltage per unit charge
- d) Charge per unit length
  Answer: b) Force per unit charge
The SI unit of electric field strength is:
- a) Newton
- b) Volt
- c) Volt per meter
- d) Ampere
  Answer: c) Volt per meter
The direction of the electric field created by a positive charge is:
- a) Toward the charge
- b) Away from the charge
- c) Perpendicular to the charge
- d) In the direction of the force
  Answer: b) Away from the charge
The electric field due to a point charge decreases as:
- a) The charge increases
- b) The distance from the charge decreases
- c) The distance from the charge increases
- d) The charge decreases
  Answer: c) The distance from the charge increases
The potential difference between two points is the:
- a) Work done in moving a unit charge from one point to another
- b) Force per unit charge
- c) Charge per unit length
- d) Current between the points
  Answer: a) Work done in moving a unit charge from one point to another
The SI unit of electric potential is:
- a) Ampere
- b) Volt
- c) Coulomb
- d) Ohm
  Answer: b) Volt
Which of the following is a scalar quantity?
- a) Electric field
- b) Electric force
- c) Electric potential
- d) Electric flux
  Answer: c) Electric potential
The electric potential at a point due to a point charge is:
- a) Directly proportional to the charge
- b) Inversely proportional to the charge
- c) Directly proportional to the distance from the charge
- d) Inversely proportional to the distance from the charge
  Answer: a) Directly proportional to the charge
A conductor is a material that:
- a) Does not allow electric charges to flow through it
- b) Allows electric charges to flow through it easily
- c) Has high resistance to electric current
- d) Does not conduct electric current
  Answer: b) Allows electric charges to flow through it easily
In a parallel plate capacitor, the capacitance depends on:
- a) The charge
- b) The potential difference
- c) The area of the plates
- d) The distance between the plates
  Answer: c) The area of the plates
The capacitance of a capacitor is:
- a) Directly proportional to the charge and inversely proportional to the potential difference
- b) Directly proportional to the potential difference and inversely proportional to the charge
- c) Inversely proportional to the charge and directly proportional to the potential difference
- d) Directly proportional to the charge and directly proportional to the potential difference
  Answer: a) Directly proportional to the charge and inversely proportional to the potential difference
The unit of capacitance is:
- a) Farad
- b) Coulomb per volt
- c) Volt per meter
- d) Ohm
  Answer: a) Farad
The energy stored in a capacitor is given by:
- a) (1/2)CV²
- b) CV
- c) (1/2)Q²/C
- d) QV
  Answer: a) (1/2)CV²
In a series circuit, the total capacitance is:
- a) The sum of individual capacitances
- b) The reciprocal of the sum of the reciprocals of individual capacitances
- c) The product of individual capacitances
- d) The average of individual capacitances
  Answer: b) The reciprocal of the sum of the reciprocals of individual capacitances
The electric potential inside a conductor in electrostatic equilibrium is:
- a) Zero
- b) Constant
- c) Varies with position
- d) Maximum at the surface
  Answer: b) Constant
A capacitor is charged by connecting it to:
- a) A resistor
- b) A battery
- c) A capacitor of the same capacitance
- d) A switch
  Answer: b) A battery
The electric field inside a charged hollow conductor is:
- a) Maximum
- b) Zero
- c) Minimum
- d) Varies with distance
  Answer: b) Zero
If the distance between the plates of a parallel plate capacitor is doubled, the capacitance:
- a) Doubles
- b) Halves
- c) Remains the same
- d) Quadruples
  Answer: b) Halves
The electric field between the plates of a parallel plate capacitor is:
- a) Directly proportional to the charge
- b) Inversely proportional to the charge
- c) Directly proportional to the potential difference
- d) Inversely proportional to the potential difference
  Answer: c) Directly proportional to the potential difference
In an electric circuit, a capacitor can be used to:
- a) Increase resistance
- b) Store energy
- c) Decrease voltage
- d) Increase current
  Answer: b) Store energy
A dielectric material is inserted between the plates of a capacitor. The effect on capacitance is:
- a) Decreases
- b) Increases
- c) Remains unchanged
- d) Depends on the charge
  Answer: b) Increases
The force between two point charges of +2 C and -3 C separated by a distance of 2 meters is given by Coulomb’s law. If the charges are doubled, the force will be:
- a) The same
- b) Twice as much
- c) Four times as much
- d) Eight times as much
  Answer: d) Eight times as much
The electric field inside a uniformly charged sphere is:
- a) Zero
- b) Constant
- c) Directly proportional to the distance from the center
- d) Inversely proportional to the distance from the center
  Answer: c) Directly proportional to the distance from the center
The electric flux through a closed surface is proportional to:
- a) The charge enclosed by the surface
- b) The area of the surface
- c) The distance from the charge
- d) The potential difference
  Answer: a) The charge enclosed by the surface
In a conductor, free charges are:
- a) Fixed in position
- b) Restricted to the surface
- c) Free to move
- d) Bound to atoms
  Answer: c) Free to move
If the potential difference across a capacitor is halved, the stored energy in the capacitor is:
- a) The same
- b) Halved
- c) Quartered
- d) Doubled
  Answer: c) Quartered
The direction of the electric field at any point is given by:
- a) The direction of the force on a positive test charge
- b) The direction of the force on a negative test charge
- c) The direction of the current
- d) The direction of the magnetic field
  Answer: a) The direction of the force on a positive test charge
The capacitance of a capacitor can be increased by:
- a) Decreasing the distance between the plates
- b) Increasing the distance between the plates
- c) Decreasing the area of the plates
- d) Using a dielectric with lower permittivity
  Answer: a) Decreasing the distance between the plates
The principle of superposition states that:
- a) The net electric field is the sum of the individual fields
- b) The net charge is the sum of individual charges
- c) The electric potential is the product of individual potentials
- d) The force is the difference of individual forces
  Answer: a) The net electric field is the sum of the individual fields
The electric potential due to a positive point charge is:
- a) Zero at infinity
- b) Positive everywhere
- c) Negative everywhere
- d) Zero at the point charge
  Answer: b) Positive everywhere
The electric field due to a uniform line of charge is:
- a) Uniform everywhere
- b) Zero everywhere
- c) Decreases with distance from the line
- d) Increases with distance from the line
  Answer: c) Decreases with distance from the line
The potential difference across a capacitor is directly proportional to:
- a) The charge on the capacitor
- b) The capacitance of the capacitor
- c) The current through the capacitor
- d) The resistance in the circuit
  Answer: a) The charge on the capacitor
Which of the following is true for a conductor in electrostatic equilibrium?
- a) The electric field inside is zero
- b) The electric field inside is uniform
- c) The electric field outside is zero
- d) The charge is evenly distributed throughout the volume
  Answer: a) The electric field inside is zero
The force between two point charges is 10 N. If the distance between them is tripled, the new force is:
- a) 10 N
- b) 3.33 N
- c) 30 N
- d) 1.11 N
  Answer: d) 1.11 N
The electric potential inside a charged spherical shell is:
- a) Maximum at the center
- b) Zero everywhere
- c) Minimum at the center
- d) Varies with distance from the shell
  Answer: b) Zero everywhere
The potential difference between two points is given by:
- a) The product of the electric field and the distance
- b) The ratio of the electric field to the distance
- c) The product of the electric field and the charge
- d) The charge divided by the distance
  Answer: a) The product of the electric field and the distance
The electric field inside a conductor is:
- a) Zero
- b) Maximum at the center
- c) Equal to the potential difference
- d) Constant throughout
  Answer: a) Zero
In an isolated charged conductor, the charge resides:
- a) Inside the bulk of the conductor
- b) On the surface of the conductor
- c) At the center of the conductor
- d) Inside a cavity within the conductor
  Answer: b) On the surface of the conductor
The work done in moving a charge in an electric field is:
- a) Equal to the change in electric potential
- b) Equal to the change in electric field
- c) Equal to the product of charge and field
- d) Independent of the path taken
  Answer: a) Equal to the change in electric potential
The electric potential energy of a system of charges is:
- a) The work done to assemble the charges
- b) The product of the charges and the distance
- c) The force between the charges
- d) The charge times the electric field
  Answer: a) The work done to assemble the charges
The force between two charges of +3 μC and -3 μC separated by 5 meters is:
- a) 1.8 × 10⁻⁹ N
- b) 1.8 × 10⁻² N
- c) 1.8 × 10⁻⁶ N
- d) 1.8 × 10⁻⁴ N
  Answer: b) 1.8 × 10⁻² N
The electric field inside a uniformly charged insulating sphere is:
- a) Zero
- b) Directly proportional to the distance from the center
- c) Inversely proportional to the distance from the center
- d) Constant
  Answer: b) Directly proportional to the distance from the center
The electric potential due to a system of charges is:
- a) The sum of potentials due to individual charges
- b) The difference of potentials due to individual charges
- c) The product of potentials due to individual charges
- d) The average of potentials due to individual charges
  Answer: a) The sum of potentials due to individual charges
When a dielectric is introduced between the plates of a capacitor, the electric field between the plates:
- a) Increases
- b) Decreases
- c) Remains unchanged
- d) Becomes zero
  Answer: b) Decreases
The electric field outside a uniformly charged sphere behaves as if:
- a) All the charge were concentrated at the center
- b) The sphere were uncharged
- c) The charge were uniformly distributed throughout the volume
- d) The charge were uniformly distributed on the surface
  Answer: a) All the charge were concentrated at the center
The electric potential energy of a positive charge in a uniform electric field is:
- a) Zero
- b) Negative
- c) Positive
- d) Dependent on the direction of the field
  Answer: c) Positive
In a parallel plate capacitor, the potential difference between the plates is directly proportional to:
- a) The charge on the plates
- b) The area of the plates
- c) The distance between the plates
- d) The dielectric constant
  Answer: a) The charge on the plates
In an isolated conductor, the charge resides:
- a) Only on the surface
- b) Only in the interior
- c) Equally distributed on the surface and interior
- d) At the center of the conductor
  Answer: a) Only on the surface
The electric field inside a charged spherical conductor is:
- a) Zero
- b) Maximum at the center
- c) Minimum at the center
- d) Constant throughout
  Answer: a) Zero
The electric potential at a point due to a positive point charge is:
- a) Zero at infinity
- b) Positive everywhere
- c) Negative everywhere
- d) Zero at the point charge
  Answer: b) Positive everywhere
The capacitance of a capacitor is defined as:
- a) Charge per unit voltage
- b) Voltage per unit charge
- c) Charge per unit area
- d) Voltage per unit area
  Answer: a) Charge per unit voltage
The electric field lines for a positive point charge are:
- a) Divergent and start from the charge
- b) Convergent and end at the charge
- c) Circular and centered around the charge
- d) Parallel and straight lines
  Answer: a) Divergent and start from the charge
The electric potential due to a system of charges is:
- a) The algebraic sum of potentials due to individual charges
- b) The product of potentials due to individual charges
- c) The average of potentials due to individual charges
- d) The difference of potentials due to individual charges
  Answer: a) The algebraic sum of potentials due to individual charges
The energy stored in a capacitor is directly proportional to:
- a) The square of the potential difference
- b) The charge on the capacitor
- c) The capacitance
- d) The current through the capacitor
  Answer: a) The square of the potential difference
The electric field due to a positive charge is:
- a) Uniform in all directions
- b) Radial and directed away from the charge
- c) Radial and directed towards the charge
- d) Perpendicular to the direction of the charge
  Answer: b) Radial and directed away from the charge
The unit of electric potential energy is:
- a) Joule
- b) Volt
- c) Coulomb
- d) Newton
  Answer: a) Joule
A capacitor with capacitance C is connected to a battery. If the battery voltage is doubled, the energy stored in the capacitor:
- a) Doubles
- b) Quadruples
- c) Remains the same
- d) Halves
  Answer: b) Quadruples
The electric field inside a spherical conductor is:
- a) Zero
- b) Directly proportional to the radius
- c) Inversely proportional to the radius
- d) Constant
  Answer: a) Zero
The electric potential at a point in space is a measure of:
- a) The electric field at that point
- b) The work done to bring a unit positive charge from infinity to that point
- c) The force experienced by a unit positive charge at that point
- d) The charge present at that point
  Answer: b) The work done to bring a unit positive charge from infinity to that point
The capacitance of a capacitor is:
- a) Inversely proportional to the potential difference
- b) Directly proportional to the potential difference
- c) Inversely proportional to the charge
- d) Directly proportional to the charge
  Answer: d) Directly proportional to the charge
A parallel plate capacitor is charged to a potential difference of 12 V. If the distance between the plates is increased, the potential difference:
- a) Increases
- b) Decreases
- c) Remains the same
- d) Depends on the charge
  Answer: a) Increases
The electric field between two parallel plates is:
- a) Zero
- b) Constant and directed from positive to negative
- c) Constant and directed from negative to positive
- d) Varies with distance from the plates
  Answer: b) Constant and directed from positive to negative
The electric potential energy of a capacitor is:
- a) The work done to charge the capacitor
- b) The energy stored due to the electric field between the plates
- c) The energy lost as heat
- d) The charge divided by the voltage
  Answer: b) The energy stored due to the electric field between the plates
If the distance between the plates of a capacitor is halved, the electric field between the plates:
- a) Doubles
- b) Halves
- c) Remains the same
- d) Becomes zero
  Answer: a) Doubles
The force experienced by a unit positive charge in an electric field is called:
- a) Electric potential
- b) Electric potential energy
- c) Electric force
- d) Electric field strength
  Answer: d) Electric field strength
The total charge on a capacitor is:
- a) Directly proportional to the capacitance
- b) Inversely proportional to the capacitance
- c) Directly proportional to the potential difference
- d) Inversely proportional to the potential difference
  Answer: a) Directly proportional to the capacitance
The electric field due to a uniformly charged infinite plane sheet is:
- a) Zero
- b) Uniform and independent of distance from the sheet
- c) Varies with the distance from the sheet
- d) Depends on the charge on the sheet
  Answer: b) Uniform and independent of distance from the sheet
The electric potential inside a charged conductor is:
- a) Variable
- b) Zero
- c) Constant
- d) Maximum at the surface
  Answer: c) Constant
The energy stored in a capacitor is:
- a) Directly proportional to the capacitance and square of the voltage
- b) Directly proportional to the capacitance and voltage
- c) Inversely proportional to the capacitance and voltage
- d) Directly proportional to the square of the charge
  Answer: a) Directly proportional to the capacitance and square of the voltage
The electric field due to a charged infinite line of charge decreases with:
- a) The square of the distance from the line
- b) The distance from the line
- c) The cube of the distance from the line
- d) The logarithm of the distance from the line
  Answer: b) The distance from the line
The electric field inside a charged conducting sphere is:
- a) Zero
- b) Maximum at the center
- c) Directly proportional to the radius
- d) Inversely proportional to the radius
  Answer: a) Zero
The electric potential due to a uniformly charged ring at a point along its axis is:
- a) Maximum at the center of the ring
- b) Zero at the center of the ring
- c) Varies with distance from the ring
- d) Constant everywhere along the axis
  Answer: c) Varies with distance from the ring
In a circuit with capacitors in series, the equivalent capacitance is:
- a) The sum of individual capacitances
- b) The reciprocal of the sum of the reciprocals of individual capacitances
- c) The average of individual capacitances
- d) The product of individual capacitances
  Answer: b) The reciprocal of the sum of the reciprocals of individual capacitances
The energy stored in a capacitor with capacitance C and charge Q is given by:
- a) Q² / C
- b) CV
- c) QV / 2
- d) (1/2)CV²
  Answer: d) (1/2)CV²
The electric field between two points in space is:
- a) The rate of change of potential with distance
- b) The rate of change of charge with distance
- c) The rate of change of current with distance
- d) The rate of change of capacitance with distance
  Answer: a) The rate of change of potential with distance
The electric field strength at a point is:
- a) The force experienced by a unit positive charge placed at that point
- b) The potential difference per unit length
- c) The product of charge and distance
- d) The voltage across the point
  Answer: a) The force experienced by a unit positive charge placed at that point
If two capacitors of capacitance C₁ and C₂ are connected in parallel, the total capacitance is:
- a) C₁ + C₂
- b) C₁ × C₂ / (C₁ + C₂)
- c) C₁ / C₂
- d) (C₁ + C₂) / 2
  Answer: a) C₁ + C₂
The electric potential due to a positive charge at a certain distance is:
- a) Directly proportional to the distance
- b) Inversely proportional to the distance
- c) Zero at that distance
- d) Independent of the distance
  Answer: b) Inversely proportional to the distance
The energy stored in a capacitor is used to:
- a) Create a potential difference across the plates
- b) Increase the capacitance
- c) Decrease the distance between the plates
- d) Generate an electric field between the plates
  Answer: a) Create a potential difference across the plates
The electric field inside a uniformly charged insulating sphere increases with:
- a) The distance from the center of the sphere
- b) The square of the distance from the center
- c) The inverse of the distance from the center
- d) The radius of the sphere
  Answer: a) The distance from the center of the sphere
The electric potential at a point due to a system of charges is:
- a) The algebraic sum of potentials due to individual charges
- b) The vector sum of electric fields due to individual charges
- c) The average of potentials due to individual charges
- d) The product of potentials due to individual charges
  Answer: a) The algebraic sum of potentials due to individual charges
The electric field at a point outside a uniformly charged spherical shell is:
- a) Zero
- b) Uniform
- c) Varies with distance
- d) Acts as if all the charge were at the center
  Answer: d) Acts as if all the charge were at the center
The electric potential due to a negative point charge is:
- a) Zero everywhere
- b) Positive everywhere
- c) Negative everywhere
- d) Zero at the point charge
  Answer: c) Negative everywhere
The energy stored in a capacitor depends on:
- a) Capacitance and potential difference
- b) Capacitance and charge
- c) Potential difference and charge
- d) Charge and distance between plates
  Answer: a) Capacitance and potential difference
The electric field strength inside a charged spherical conductor is:
- a) Zero
- b) Maximum at the surface
- c) Directly proportional to the radius
- d) Varies with distance from the center
  Answer: a) Zero
The capacitance of a capacitor with a dielectric material is:
- a) Decreased
- b) Increased
- c) Unchanged
- d) Halved
  Answer: b) Increased
The electric potential at a point in space is the work done to:
- a) Move a unit positive charge from infinity to that point
- b) Bring a charge from one point to another
- c) Generate an electric field at that point
- d) Remove a charge from that point
  Answer: a) Move a unit positive charge from infinity to that point
The force between two charges is inversely proportional to:
- a) The square of the distance between them
- b) The distance between them
- c) The product of the charges
- d) The sum of the charges
  Answer: a) The square of the distance between them
The energy stored in a capacitor with capacitance C and voltage V is:
- a) (1/2)CV
- b) (1/2)CV²
- c) (1/2)QV²
- d) (1/2)Q² / C
  Answer: b) (1/2)CV²
The electric potential due to a charge distribution is:
- a) The sum of potentials due to individual charges
- b) The product of potentials due to individual charges
- c) The average of potentials due to individual charges
- d) The difference of potentials due to individual charges
  Answer: a) The sum of potentials due to individual charges
In a capacitor, the electric potential energy is stored due to:
- a) The separation of positive and negative charges
- b) The movement of charges
- c) The magnetic field between the plates
- d) The resistance of the material
  Answer: a) The separation of positive and negative charges
The electric field lines between two parallel plates are:
- a) Uniform and parallel
- b) Radial and directed towards the positive plate
- c) Convergent at the center
- d) Circular around the edges
  Answer: a) Uniform and parallel
The capacitance of a capacitor is given by:
- a) C = Q / V
- b) C = V / Q
- c) C = Q × V
- d) C = V / Q²
  Answer: a) C = Q / V
The electric field due to a charged disk at a point along its axis is:
- a) Uniform and constant
- b) Decreases with distance from the disk
- c) Increases with distance from the disk
- d) Zero at the center of the disk
  Answer: b) Decreases with distance from the disk
The electric potential at a point is a measure of:
- a) The electric field strength
- b) The force experienced by a unit positive charge
- c) The work done in bringing a unit positive charge from infinity to that point
- d) The distance of the point from the charge
  Answer: c) The work done in bringing a unit positive charge from infinity to that point
The electric field due to a point charge decreases with: – a) The square of the distance from the charge – b) The distance from the charge – c) The cube of the distance from the charge – d) The logarithm of the distance from the charge
Answer: a) The square of the distance from the charge