A charged particle moves through a magnetic field in a direction perpendicular to the field. Which quantity remains unchanged?
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A charged particle moves through a magnetic field in a direction perpendicular to the field. Which quantity remains unchanged?

G1 Physics · Accepted Answer

Step 1: Magnetic force is always perpendicular to particle velocity: F⃗=q(v⃗×B⃗). Step 2: It changes the direction of momentum but power F⃗·v⃗ remains zero. Step 3: Therefore speed remains unchanged even though direction/acceleration change. Answer A. Final answer: (A) speed of the particle remains unchanged.