Class 12 Physics MCQ Chapter 1 Electric Charges and Fields
Start your Physics exam preparation with our Class 12 Physics MCQ Chapter 1 Electric Charges and Fields English Medium study material. This article offers a carefully selected collection of multiple-choice questions (MCQs) with answers based on the latest AHSEC syllabus, helping students build a strong foundation in Electrostatics.
The chapter Electric Charges and Fields introduces fundamental concepts such as electric charge, conservation of charge, Coulomb’s law, electric field, electric field lines, electric flux, and Gauss’s law. These topics form the basis for many advanced chapters in Physics and are frequently featured in board examinations. Practicing these MCQs will help students improve their conceptual understanding and develop the confidence needed to solve objective questions accurately.
All questions are designed to match the AHSEC examination pattern and are suitable for quick revision, self-assessment, and exam preparation. Whether you are studying the chapter for the first time or revising before the final examination, these MCQ solutions will help you identify important concepts and improve your performance.
Regular practice of these Chapter 1 MCQs can enhance problem-solving skills, increase accuracy, and help students score better marks in Physics examinations.
Part: I
Electric Charges and Fields
VSA & MCQ
I. Very Short Answer Questions
Q. What is electric charge?
Ans: Electric charge is a fundamental property of matter that causes it to experience a force in an electric field.
Q. What are the types of electric charge?
Ans: Positive charge and negative charge.
Q. State the law of conservation of charge.
Ans: The total electric charge of an isolated system remains constant.
Q. What is the SI unit of charge?
Ans: Coulomb (C).
Q. What is Coulomb’s law?
Ans: The force between two charges is F = (1 / (4πε₀)) × (q₁q₂ / r²).
Q. Define electric field.
Ans: Electric field is the force per unit charge at a point, E = F / q.
Q. What is the direction of electric field?
Ans: The direction of force on a positive test charge.
Q. What is a point charge?
Ans: A charge whose size is negligible compared to the distance.
Q. What is electric field intensity due to a point charge?
Ans: E = (1 / (4πε₀)) × (q / r²).
Q. What is a dipole?
Ans: A pair of equal and opposite charges separated by a small distance.
Q. Define dipole moment.
Ans: Dipole moment p = q × 2a.
Q. What is the SI unit of dipole moment?
Ans: Coulomb-meter (C·m).
Q. What is an electric field line?
Ans: A curve representing the direction of electric field.
Q. Do electric field lines intersect?
Ans: No.
Q. What is electric flux?
Ans: Electric flux is the number of electric field lines passing through a surface.
Q. Write expression for electric flux.
Ans: Φ = E · A cosθ.
Q. State Gauss’s law.
Ans: Total flux = q_enclosed / ε₀.
Q. What is a Gaussian surface?
Ans: An imaginary closed surface used to apply Gauss’s law.
Q. What is the field inside a conductor?
Ans: Zero.
Q. What is the charge distribution in a conductor?
Ans: Charges reside on the surface.
Q. What is electrostatic shielding?
Ans: Protection from external electric fields using conductors.
Q. What is permittivity of free space?
Ans: ε₀ ≈ 8.85 × 10⁻¹² C² N⁻¹ m⁻².
Q. What is superposition principle?
Ans: Net force is the vector sum of individual forces.
Q. What is uniform electric field?
Ans: Field with constant magnitude and direction.
Q. What is non-uniform field?
Ans: Field varying with position.
Q. What is electric field inside a charged shell?
Ans: Zero.
Q. What is electric field outside a charged sphere?
Ans: Same as a point charge.
Q. What is surface charge density?
Ans: Charge per unit area, σ = q / A.
Q. What is volume charge density?
Ans: ρ = q / V.
Q. What is linear charge density?
Ans: λ = q / L.
II. Multiple Choice Questions
Q. The SI unit of electric charge is:
(a) Ampere
(b) Coulomb
(c) Volt
(d) Ohm
Ans: (b)
Q. Like charges:
(a) Attract
(b) Repel
(c) Neutralize
(d) Rotate
Ans: (b)
Q. Coulomb’s law is valid for:
(a) Only conductors
(b) Only insulators
(c) Point charges
(d) Large bodies
Ans: (c)
Q. Electric field is a:
(a) Scalar
(b) Vector
(c) Tensor
(d) Constant
Ans: (b)
Q. Electric field lines start from:
(a) Negative charge
(b) Positive charge
(c) Neutral point
(d) Infinity
Ans: (b)
Q. Electric field inside a conductor is:
(a) Maximum
(b) Minimum
(c) Zero
(d) Infinite
Ans: (c)
Q. Unit of electric field is:
(a) N/C
(b) C/N
(c) J
(d) W
Ans: (a)
Q. Electric flux depends on:
(a) Area
(b) Field
(c) Angle
(d) All of these
Ans: (d)
Q. Gauss law is applicable for:
(a) Any surface
(b) Only closed surface
(c) Only open surface
(d) No surface
Ans: (b)
Q. Dipole moment depends on:
(a) Charge only
(b) Distance only
(c) Both charge and distance
(d) Neither
Ans: (c)
Q. Assertion: Electric field lines never intersect. Reason: At intersection, field would have two directions.
(a) Both true, reason correct
(b) Both true, reason incorrect
(c) Assertion true, reason false
(d) Both false
Ans: (a)
Q. Assertion: Electric field inside conductor is zero. Reason: Charges are free to move.
(a) Both true, reason correct
(b) Both true, reason incorrect
(c) Assertion true, reason false
(d) Both false
Ans: (a)
Q. Assertion: Coulomb force decreases with distance. Reason: F ∝ 1/r².
(a) Both true, reason correct
(b) Both true, reason incorrect
(c) Assertion true, reason false
(d) Both false
Ans: (a)
Q. Assertion: Electric flux is scalar. Reason: It depends on dot product.
(a) Both true, reason correct
(b) Both true, reason incorrect
(c) Assertion true, reason false
(d) Both false
Ans: (a)
Q. Assertion: Field lines are continuous. Reason: They start and end on charges.
(a) Both true, reason correct
(b) Both true, reason incorrect
(c) Assertion true, reason false
(d) Both false
Ans: (b)
Q. Assertion: Gaussian surface is real. Reason: Used in experiments.
(a) Both true
(b) Both false
(c) Assertion true, reason false
(d) Assertion false, reason true
Ans: (b)
Q. Assertion: Electric field is zero at center of charged shell. Reason: Symmetry cancels field.
(a) Both true, reason correct
(b) Both true, reason incorrect
(c) Assertion true, reason false
(d) Both false
Ans: (a)
