Question

The figure shows three situations when an electron with velocity travels through a uniform magnetic field . In each case, what is the direction of magnetic force on the electron?

• A. +ve z-axis, –ve x-axis, +ve y-axis
• B. –ve z-axis, –ve x-axis and zero
• C. +ve z-axis, +ve y-axis and zero
• D. –ve z-axis, +ve x-axis and zero

Answer 1

Answer: (B)

–ve z-axis, –ve x-axis and zero

Answer 2

Use = q () = (–e) ()