Quiz — BHP301

Q1. Gauss's law states that the total electric flux through a closed surface equals:

A. Zero always B. Q_enclosed / ε0 C. Q_enclosed × ε0 D. The surface area times the field

Q2. The electric field outside a uniformly charged sphere behaves as if:

A. All the charge is spread uniformly on the surface only B. All the charge were concentrated at its centre C. There is no field at all D. The field is independent of distance

Q3. The electrostatic field is conservative, meaning:

A. ∮E·dl ≠ 0 in general B. ∮E·dl = 0 around any closed loop C. E always points radially outward D. E does maximum work around any loop

Q4. Poisson's equation in electrostatics is:

A. ∇²V = 0 B. ∇²V = -ρ/ε0 C. ∇·E = 0 everywhere D. ∇×E = -ρ/ε0

Q5. Laplace's equation applies specifically to regions:

A. Containing free charge B. With no charge (ρ = 0) C. With only magnetic fields D. Where E is zero

Q6. The Uniqueness theorem in electrostatics guarantees that:

A. Multiple different potentials can satisfy the same boundary conditions B. A solution satisfying Laplace/Poisson equation and the correct boundary conditions is the only solution C. No solution ever exists D. Boundary conditions are irrelevant

Q7. The potential due to an electric dipole falls off with distance as:

A. 1/r B. 1/r² C. 1/r³ D. Independent of r

Q8. The torque on a dipole in a uniform external field is given by:

A. τ = p·E B. τ = p × E C. τ = p/E D. τ = p + E

Q9. Energy stored in a capacitor of capacitance C charged to voltage V is:

A. CV B. ½CV² C. C/V D. 2CV²

Q10. The net force on an electric dipole in a UNIFORM external field is:

A. Maximum B. Zero C. Proportional to field squared D. Always attractive

Q11. Electric displacement D is related to E and polarization P by:

A. D = ε0E - P B. D = ε0E + P C. D = P/ε0 - E D. D = E - P/ε0

Q12. Gauss's law in terms of D depends only on:

A. Bound (polarization) charge B. Free charge enclosed C. Total charge including image charges D. Nothing; it is always zero

Q13. For a linear dielectric, P is related to E by:

A. P = ε0χe E B. P = χe / E C. P = E / χe D. P = ε0 / (χe E)

Q14. At a dielectric-dielectric interface with no free charge, the boundary condition states:

A. Both D and E are always fully continuous B. The normal component of D is continuous, tangential E is continuous C. Neither D nor E is continuous D. D jumps discontinuously always

Q15. Filling a parallel plate capacitor completely with a dielectric of constant εr increases capacitance by a factor of:

A. 1/εr B. εr C. εr² D. No change occurs

Q16. The Lorentz force law is given by:

A. F = qE only B. F = q(E + v × B) C. F = qv only D. F = qB only

Q17. The magnetic component of the Lorentz force on a moving charge:

A. Does work on the charge B. Never does work on the charge (always ⟂ to velocity) C. Always accelerates the charge along its motion D. Reverses the charge's sign

Q18. The Biot–Savart law gives the magnetic field due to:

A. A static point charge B. A current element C. A dielectric slab D. A magnetic monopole

Q19. The magnetic field at the centre of a circular current loop of radius R carrying current I is:

A. μ0I/2R B. μ0I/(2πR) C. μ0NI/(4R) D. μ0I R/2

Q20. Ampere's circuital law states:

A. ∮B·dl = μ0 I_enclosed B. ∮B·dA = μ0 I_enclosed C. ∮E·dl = μ0 I_enclosed D. ∮B·dl = 0 always

Q21. The magnetic field inside a long solenoid (using Ampere's law) is:

A. Zero B. B = μ0 n I, where n is turns per unit length C. B = μ0 I / (2πr) D. Dependent only on the solenoid's diameter

Q22. The torque on a magnetic dipole of moment m in an external field B is:

A. τ = m·B B. τ = m × B C. τ = m / B D. τ = m + B

Q23. Diamagnetic materials have magnetic susceptibility that is:

A. Large and positive B. Small and negative C. Exactly zero D. Large and negative

Q24. Ferromagnetic materials are characterized by:

A. Very weak, temperature-independent magnetization B. Spontaneous magnetization and hysteresis C. Zero magnetic susceptibility D. Repulsion from all magnetic fields

Q25. Paramagnetic susceptibility is generally:

A. Large and negative B. Small and positive C. Exactly zero always D. Independent of temperature in all cases

Q26. Faraday's law of electromagnetic induction states that the induced EMF equals:

A. The magnetic flux itself B. The negative rate of change of magnetic flux, -dΦ/dt C. The square of the magnetic flux D. Zero if flux changes

Q27. Lenz's law is fundamentally a statement of:

A. Charge conservation B. Energy conservation (induced effects oppose the change producing them) C. Angular momentum conservation only D. Mass conservation

Q28. Self-inductance L relates current in a circuit to:

A. The flux linkage in a neighbouring circuit B. The flux linkage produced in the same circuit C. The circuit's resistance only D. The circuit's capacitance only

Q29. Mutual inductance M describes:

A. Flux linkage in one circuit due to current in another circuit B. Only the self-flux of a single coil C. The resistance between two coils D. Capacitive coupling only

Q30. Energy stored in an inductor carrying current I is:

A. LI B. ½LI² C. L/I D. 2LI²

Q31. The RMS value of a sinusoidal voltage with peak V0 is:

A. V0 B. V0/2 C. V0/√2 D. 2V0

Q32. The impedance of a pure inductor in an AC circuit is:

A. R B. jωL C. 1/(jωC) D. Zero always

Q33. The impedance of a pure capacitor in an AC circuit is:

A. jωL B. R C. 1/(jωC) D. ωC

Q34. Series RLC resonance occurs when:

A. ωL = R B. ωL = 1/(ωC) C. ωC = R D. R = 1/(ωL)+ωC

Q35. At series resonance, the circuit's impedance is:

A. Purely reactive and maximum B. Purely resistive and minimum (equal to R) C. Infinite D. Zero

Q36. Real power in an AC circuit is given by:

A. P = VI B. P = VI cosφ C. P = VI sinφ D. P = V/I

Q37. Power factor cosφ indicates:

A. The circuit's resistance value only B. How effectively electrical power is being converted to useful work C. The circuit's capacitance only D. The frequency of the AC supply

Q38. Reactive power in an AC circuit is expressed as:

A. Q = VI cosφ B. Q = VI sinφ C. Q = VI D. Q = V/I

Q39. Kirchhoff's Current Law (KCL) is based on:

A. Conservation of energy B. Conservation of charge at a node C. Conservation of magnetic flux D. Ohm's law only

Q40. Kirchhoff's Voltage Law (KVL) is based on:

A. Conservation of charge B. The conservative nature of the electrostatic field (sum of voltage drops around a loop = 0) C. Ampere's law D. Faraday's law strictly

Q41. Thevenin's theorem replaces a linear two-terminal network with:

A. A current source in parallel with a resistance B. A voltage source in series with a resistance C. Two independent voltage sources D. An inductor only

Q42. Norton's theorem is the dual of Thevenin's theorem, replacing the network with:

A. A voltage source in series with resistance B. A current source in parallel with a resistance C. A capacitor only D. A pure inductor

Q43. The superposition theorem applies only to circuits that are:

A. Non-linear B. Linear, with multiple independent sources C. Purely resistive with one source only D. Made only of capacitors

Q44. When applying superposition, an unused ideal voltage source is replaced by:

A. An open circuit B. A short circuit C. A large resistor D. Another voltage source

Q45. The Maximum Power Transfer theorem states maximum power is delivered to the load when:

A. Load resistance is zero B. Load resistance equals the Thevenin resistance of the source network C. Load resistance is infinite D. Load resistance is twice the source resistance

Q46. Maxwell introduced the concept of displacement current to:

A. Replace Faraday's law entirely B. Make Ampere's law consistent with the continuity equation when charge accumulates (e.g. capacitor charging) C. Eliminate the need for Gauss's law D. Increase magnetic field strength artificially

Q47. Displacement current density is given by:

A. Jd = ε0 ∂E/∂t B. Jd = σE C. Jd = μ0 H D. Jd = ∇×B

Q48. Maxwell's equations predict that electromagnetic waves in vacuum travel at speed:

A. c = μ0ε0 B. c = 1/√(μ0ε0) C. c = √(μ0/ε0) D. c = μ0/ε0

Q49. The Poynting vector S represents:

A. Electric charge density B. The direction and rate of energy flow in an electromagnetic field C. Magnetic flux only D. Electric potential

Q50. Gauss's law for magnetism (∮B·dA = 0) implies that:

A. Magnetic monopoles exist abundantly B. Magnetic field lines have no beginning or end (no magnetic monopoles) C. Magnetic fields cannot exist in vacuum D. B is always zero

BHP30150-Question MCQ Quiz