NEET Physics: continuous charge distribution Practice Questions
13 free multiple-choice questions on continuous charge distribution (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 NEET questions in the app →Q1. If a charge is distributed uniformly over a volume V, the volume charge density (ρ) is defined as the total charge divided by:
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Correct answer: B — The volume itself
Volume charge density (ρ) is defined as the total charge (Q) divided by the total volume (V), i.e., ρ= Q/V.
Q2. For a continuous charge distribution along a line, the electric field E at a point is proportional to:
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Correct answer: C — the linear charge density λ
The electric field produced by a continuous charge distribution (like a line) is directly proportional to the linear charge density λ and inversely proportional to the distance r from the line.
Q3. If the charge density on a wire is λ, and we consider a small segment of length dx, the charge dq on this segment is given by:
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Correct answer: A — dq = λdx
For a uniform distribution, the infinitesimal charge dq is the density λ multiplied by the infinitesimal length dx: dq = λdx
Q4. A continuous charge distribution is spread over a surface. The surface charge density σ is defined as:
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Correct answer: D — Charge per unit area
Surface charge density σ is defined as the total charge Q divided by the total area A over which it is distributed: σ= Q/A
Q5. A thin, uniformly charged rod of length L and linear charge density λ is bent into a semicircle. The charge density per unit length along the arc is proportional to the arc length. How does the total charge compare to that of a straight rod of the same length?
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Correct answer: D — Equal to straight rod
Since the charge density is defined along the arc length, and the length of the arc is Lπ, the total charge is proportional to the total length, regardless of the curvature, provided the density distribution is physically defined across the path. If the density is uniform along the path, the total charge remains the same as a straight rod of length L.
Q6. If a uniformly charged rod of length L has a total charge Q, what is the linear charge density of the rod?
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Correct answer: C — Q/L
Linear charge density (λ) is defined as the total charge (Q) distributed over the total length (L) of the line. Thus, λ= Q/L.
Q7. A uniformly charged wire of length L carries a linear charge density λ. What is the total charge on the wire?
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Correct answer: C — λL
The total charge (Q) in a continuous distribution is found by multiplying the density (λ) by the total length (L). Thus, Q = λL
Q8. A thin, uniformly charged sheet has a surface charge density σ. If the area of the sheet is A, what is the total charge on the sheet?
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Correct answer: A — Aσ
Surface charge density (σ) is charge per unit area. The total charge (Q) is the product of the charge density and the area, so Q = σA.
Q9. A thin spherical shell has a total surface charge Q distributed uniformly over its surface. What is the surface charge density σ of the shell?
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Correct answer: D — Q / (4 πR²)
Surface charge density (σ) is defined as the total charge (Q) divided by the total surface area (A = 4 πR²). Therefore, σ= Q / (4 πR²).
Q10. A charged surface is subject to a uniform electric field E⃗. If the surface charge density σ is constant, the force per unit area experienced by the surface is given by:
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Correct answer: C — F = σE
The electric field exerts a force on the charge. For a surface charge density σ, the force per unit area is F⃗/A = σE⃗. The magnitude of the force is F = σE.
Q11. If a continuous surface charge density σ exists on a surface, and the area of that surface is A, what is the total charge Q on that surface?
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Correct answer: C — Q = σ· A
The total charge Q is the product of the charge density σ and the total area A over which it is distributed. Q = σA.
Q12. A uniform charge is distributed along a straight wire of length L with a linear charge density λ. What is the total charge on the wire?
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Correct answer: D — λL
The total charge Q is the product of the linear charge density λ and the total length L, i.e., Q = λL
Q13. If a line segment of length L carries a total charge Q, and the charge is uniformly distributed over this segment, what is the linear charge density?
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Correct answer: A — Q/L
Linear charge density λ is defined as the total charge Q divided by the length L over which the charge is distributed: λ= Q/L
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