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PHYS 2326 Exam 3 2026-2027 BANK QUESTIONS WITH
DETAILED VERIFIED ANSWERS EXAM QUESTIONS WILL
COME FROM HERE (100% CORRECT ANSWERS A+ GRADED
1. Two point charges, +Q and -Q, are placed a distance d apart. At the
midpoint between the charges, what is the direction of the electric
field?
A) Toward the positive charge
B) Toward the negative charge
C) Zero
D) Perpendicular to the line joining the charges
Answer: A) Toward the positive charge
Explanation: The electric field due to a positive charge points away
from it, while the field due to a negative charge points toward it. At the
midpoint, the field from +Q points away from +Q (toward -Q), and the
field from -Q points toward -Q (also toward -Q). Both vectors point in
the same direction: from the positive charge toward the negative
charge.
2. A hollow spherical conductor carries a net positive charge Q. Where
does the excess charge reside?
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A) Uniformly throughout the volume of the sphere
B) Only on the outer surface
C) Only on the inner surface
D) Concentrated at the center
Answer: B) Only on the outer surface
Explanation: In electrostatic equilibrium, excess charge on a conductor
resides entirely on its outer surface. The electric field inside the
conducting material must be zero, which requires any net charge to
move to the surface.
3. A parallel-plate capacitor with capacitance C is connected to a
battery of voltage V. If the plate separation is doubled while the
capacitor remains connected to the battery, what happens to the
charge on the plates?
A) It doubles
B) It remains the same
C) It is halved
D) It quadruples
Answer: C) It is halved
Explanation: Capacitance for a parallel-plate capacitor is C = ε₀A/d.
Doubling d halves C. Since the capacitor remains connected to the
battery, V is constant. From Q = CV, if C is halved and V is fixed, Q is
halved.
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4. A proton moves with velocity v perpendicular to a uniform magnetic
field B. What is the shape of its subsequent path?
A) Straight line
B) Parabola
C) Circular
D) Helix
Answer: C) Circular
Explanation: When velocity is perpendicular to a uniform magnetic
field, the magnetic force qv × B acts as a centripetal force, always
perpendicular to velocity. This produces uniform circular motion. A
helix would occur if there were a velocity component parallel to B.
5. According to Gauss's law for magnetism, which statement is true?
A) Magnetic monopoles must exist
B) The net magnetic flux through any closed surface is zero
C) Magnetic field lines can begin and end on magnetic charges
D) The magnetic field is always conservative
Answer: B) The net magnetic flux through any closed surface is zero
Explanation: Gauss's law for magnetism states ∮B·dA = 0, reflecting that
magnetic monopoles have never been observed and magnetic field
lines form continuous closed loops without beginning or end.
6. A long straight wire carries a constant current I. What is the
magnitude of the magnetic field at a distance r from the wire?
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A) μ₀I / (2πr)
B) μ₀I / (2r)
C) μ₀I / (4πr²)
D) μ₀I² / (2πr)
Answer: A) μ₀I / (2πr)
Explanation: Ampere's law for a long straight wire gives B(2πr) =
μ₀I_enclosed, yielding B = μ₀I / (2πr), an inverse-linear dependence on
distance.
7. Faraday's law states that the induced electromotive force in a loop is
proportional to:
A) The magnetic flux through the loop
B) The rate of change of magnetic flux through the loop
C) The current in the loop
D) The area of the loop
Answer: B) The rate of change of magnetic flux through the loop
Explanation: Faraday's law is ε = -dΦ_B/dt. The induced emf depends
on how rapidly the magnetic flux changes with time, not on the
instantaneous value of the flux itself.
8. An LC circuit (ideal inductor and capacitor) oscillates with angular
frequency ω. How is ω expressed?
A) ω = 1/(LC)
B) ω = 1/√(LC)
PHYS 2326 Exam 3 2026-2027 BANK QUESTIONS WITH
DETAILED VERIFIED ANSWERS EXAM QUESTIONS WILL
COME FROM HERE (100% CORRECT ANSWERS A+ GRADED
1. Two point charges, +Q and -Q, are placed a distance d apart. At the
midpoint between the charges, what is the direction of the electric
field?
A) Toward the positive charge
B) Toward the negative charge
C) Zero
D) Perpendicular to the line joining the charges
Answer: A) Toward the positive charge
Explanation: The electric field due to a positive charge points away
from it, while the field due to a negative charge points toward it. At the
midpoint, the field from +Q points away from +Q (toward -Q), and the
field from -Q points toward -Q (also toward -Q). Both vectors point in
the same direction: from the positive charge toward the negative
charge.
2. A hollow spherical conductor carries a net positive charge Q. Where
does the excess charge reside?
,2|Page
A) Uniformly throughout the volume of the sphere
B) Only on the outer surface
C) Only on the inner surface
D) Concentrated at the center
Answer: B) Only on the outer surface
Explanation: In electrostatic equilibrium, excess charge on a conductor
resides entirely on its outer surface. The electric field inside the
conducting material must be zero, which requires any net charge to
move to the surface.
3. A parallel-plate capacitor with capacitance C is connected to a
battery of voltage V. If the plate separation is doubled while the
capacitor remains connected to the battery, what happens to the
charge on the plates?
A) It doubles
B) It remains the same
C) It is halved
D) It quadruples
Answer: C) It is halved
Explanation: Capacitance for a parallel-plate capacitor is C = ε₀A/d.
Doubling d halves C. Since the capacitor remains connected to the
battery, V is constant. From Q = CV, if C is halved and V is fixed, Q is
halved.
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4. A proton moves with velocity v perpendicular to a uniform magnetic
field B. What is the shape of its subsequent path?
A) Straight line
B) Parabola
C) Circular
D) Helix
Answer: C) Circular
Explanation: When velocity is perpendicular to a uniform magnetic
field, the magnetic force qv × B acts as a centripetal force, always
perpendicular to velocity. This produces uniform circular motion. A
helix would occur if there were a velocity component parallel to B.
5. According to Gauss's law for magnetism, which statement is true?
A) Magnetic monopoles must exist
B) The net magnetic flux through any closed surface is zero
C) Magnetic field lines can begin and end on magnetic charges
D) The magnetic field is always conservative
Answer: B) The net magnetic flux through any closed surface is zero
Explanation: Gauss's law for magnetism states ∮B·dA = 0, reflecting that
magnetic monopoles have never been observed and magnetic field
lines form continuous closed loops without beginning or end.
6. A long straight wire carries a constant current I. What is the
magnitude of the magnetic field at a distance r from the wire?
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A) μ₀I / (2πr)
B) μ₀I / (2r)
C) μ₀I / (4πr²)
D) μ₀I² / (2πr)
Answer: A) μ₀I / (2πr)
Explanation: Ampere's law for a long straight wire gives B(2πr) =
μ₀I_enclosed, yielding B = μ₀I / (2πr), an inverse-linear dependence on
distance.
7. Faraday's law states that the induced electromotive force in a loop is
proportional to:
A) The magnetic flux through the loop
B) The rate of change of magnetic flux through the loop
C) The current in the loop
D) The area of the loop
Answer: B) The rate of change of magnetic flux through the loop
Explanation: Faraday's law is ε = -dΦ_B/dt. The induced emf depends
on how rapidly the magnetic flux changes with time, not on the
instantaneous value of the flux itself.
8. An LC circuit (ideal inductor and capacitor) oscillates with angular
frequency ω. How is ω expressed?
A) ω = 1/(LC)
B) ω = 1/√(LC)
