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Difficulty: MediumMagnetic Force and Electromagnetism

Match each physical electromagnetic scenario in Column I with its corresponding motion or force behavior in Column II.

  • Stationary electric charge placed inside a uniform magnetic fieldZero magnetic force because the force is directly proportional to particle speed
  • Charged particle moving perpendicular to a uniform magnetic fieldCircular trajectory produced by a magnetic force acting as a constant centripetal force
  • Positively charged particle moving North in a vertically downward magnetic fieldDeflection toward the West as predicted by the right-hand vector cross product rule
  • Two long parallel conductors carrying electric currents in the same directionMutual attractive force drawing the two conductors toward each other

Answer

Stationary charge matches zero magnetic force; Perpendicular moving charge matches circular trajectory; Positively charged particle moving North in a downward magnetic field matches deflection toward the West; Parallel conductors carrying currents in the same direction match mutual attractive force.
Each physical scenario strictly adheres to fundamental electromagnetic principles: static charges experience no magnetic force, perpendicular motion creates centripetal acceleration leading to circular paths, vector cross products govern particle deflection, and like parallel currents attract.

Step-by-Step Solution

1
Evaluate the magnetic force on a stationary charge.
Since v=0v = 0, F=q(0)Bsin⁡θ=0 NF = q(0)B\sin\theta = 0\text{ N}.
Magnetic fields only exert forces on moving charges.
2
Determine the path of a charge moving perpendicular to a uniform magnetic field.
The force is perpendicular to velocity at all points, changing direction without changing speed.
A constant perpendicular force acts as a centripetal force, resulting in a circular orbit.
3
Determine force direction for a charge moving North in a downward field.
The vector cross product of North (forward) and Downward yields West.
The direction of magnetic force on a positive charge follows F⃗=q(v⃗×B⃗)\vec{F} = q(\vec{v} \times \vec{B}).
4
Determine force interaction between parallel conductors with like currents.
The magnetic field from each wire exerts an inward force on the other wire.
Currents flowing in the same direction attract, while opposite currents repel.

Key Concept

Magnetic force on moving charges and current-carrying conductors
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Topics

Magnetic Force and Electromagnetism

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