NEET Physics: Electrostatics Practice Questions
15 free multiple-choice questions on Electrostatics for NEET Physics, each with the correct answer and a step-by-step explanation. Attempt a question, then reveal the solution to check your reasoning.
Practice thousands more Electrostatics questions in the app →Q1. For an electric dipole, the net electric field at a point on its axial line is always directed:
Show answer & explanation
Correct answer: C — Along the dipole moment vector
The electric field along the axis of a dipole is parallel to the dipole moment vector (p⃗).
Q2. Insulators generally exhibit high resistance to current flow because:
Show answer & explanation
Correct answer: A — They lack free mobile charge carriers
Insulators effectively resist current because the valence electrons are strongly localized and tightly bound to their respective atomic cores, making it very difficult for them to acquire the necessary mobility to carry charge.
Q3. Three charges q₁ = +5 μC, q₂ = -5 μC, and q₃ = +10 μC are placed such that q₁ and q₂ are separated by 1 cm and q₃ is placed outside the region between them. If q₁ and q₂ attract, and q₃ repels both, what is the net force on q₃?
Show answer & explanation
Correct answer: B — 2 × 10⁻⁹ N (repulsive)
q₁ and q₂ attract each other, and q₃ (positive) repels q₁ and q₂ (which are separated by q₃). Since q₃ is placed outside and repels the system, the net force acting on q₃ is repulsive, directed away from the charges.
Q4. The magnitude of the electric field produced by an electric dipole at a point far away from it is proportional to:
Show answer & explanation
Correct answer: D — p/r³
The electric field due to a dipole falls off as 1/r³. Since the field itself is proportional to 1/r³, the magnitude of the field scales with p/r³ (where p is the dipole moment and r is the distance).
Q5. The electric field lines are always perpendicular to the:
Show answer & explanation
Correct answer: C — Direction of the electric force
Electric field lines represent the direction of the force experienced by a positive test charge. Therefore, the field lines are always perpendicular to the surface on which they are drawn, and they point in the direction of the electric force.
Q6. Three charges, q₁ = +5 μC, q₂ = -2 μC, and q₃ = +3 μC, are arranged linearly. If q₁ is in the middle, and q₂ and q₃ are on opposite sides, which of the following statements is true regarding the forces?
Show answer & explanation
Correct answer: D — The forces exerted by q₂ and q₃ on q₁ are in opposite directions.
Since q₂ is negative and q₃ is positive, they exert forces on q₁ in opposite directions. Therefore, the net force is the difference between these two forces (superposition of forces in opposite directions).
Q7. Which material allows electric charges to move freely throughout its structure under an applied electric field?
Show answer & explanation
Correct answer: A — Conductors
Conductors possess free electrons that are able to move easily when an external potential difference is applied, allowing current flow.
Q8. If the charge stored in a capacitor is Q, and the potential difference across it is V, how is the capacitance C related to Q and V?
Show answer & explanation
Correct answer: C — C = Q/V
By definition, capacitance is the ratio of the charge (Q) stored on the plates to the potential difference (V) between the plates, so C = Q/V.
Q9. In an electrical conductor, the drift velocity of charge carriers is directly proportional to which of the following parameters?
Show answer & explanation
Correct answer: B — Electric field
Drift velocity is determined by the force applied (Electric field) and the charge carrier mobility, which is related to the electric field strength.
Q10. If two point charges have opposite signs, what type of force do they exert on each other?
Show answer & explanation
Correct answer: D — Attractive force
Charges having opposite signs (one positive and one negative) always exert an attractive force on each other.
Q11. An electric dipole of moment p is placed in a uniform electric field E. The torque experienced by the dipole is maximum when the angle between the dipole moment vector p⃗ and the electric field vector E⃗ is:
Show answer & explanation
Correct answer: C — 90°
The torque τ on an electric dipole in a uniform electric field is given by τ= pE sin θ, where θ is the angle between p⃗ and E⃗. The torque is maximum when sin θ is maximum, which occurs when θ= 90°.
Q12. The direction of the electric field lines produced by a positive point charge originates from the charge and travels in which direction?
Show answer & explanation
Correct answer: D — Away from the charge (outwards)
Electric field lines are conventionally drawn pointing away from positive charges and towards negative charges. For a positive point charge, the field lines radiate outwards, meaning the field points away from the charge.
Q13. Consider three charges q₁, q₂, q₃ placed in a line. If the force between q₁ and q₂ is attractive, and the force between q₂ and q₃ is repulsive, what must be true about the force between q₁ and q₃ for the net force to be zero?
Show answer & explanation
Correct answer: B — q₁ and q₃ must have opposite signs
For the net force to be zero (equilibrium), the forces must balance. If q₁ and q₃ have opposite signs, they will exert forces in opposite directions, allowing for a cancellation if the magnitudes are appropriately related.
Q14. Which characteristic best describes an insulator?
Show answer & explanation
Correct answer: C — Resistance to charge flow
Insulators resist charge flow due to the inability of their electrons to move freely, making them poor conductors.
Q15. Coulomb's Law describes the force between two point charges. This force is directly proportional to the product of the magnitudes of the charges and inversely proportional to the square of the:
Show answer & explanation
Correct answer: D — Distance
Coulomb's Law is F = k (|q₁ q₂|)/r². It is directly proportional to the product of the charges (q₁ q₂) and inversely proportional to the square of the distance (r²).
Keep going — practice on Padhai Karlo
Padhai Karlo gives you unlimited NEET practice: chapter-wise questions, timed quizzes, and full mock tests with an All-India Rank — free to start.
Get the free Android app →