The figure shows three situations when an electron with velocity … - Vidyadip

MCQ

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

A
positive $z-$ axis, negative $x-$ axis, positive $y-$ axis
✓
negative $z-$ axis, negative $x-$ axis and zero
C
positive $z-$ axis, positive $y-$ axis and zero
D
negative $z-$ axis, positive $x-$ axis and zero

✓

Answer

Correct option: B.

negative $z-$ axis, negative $x-$ axis and zero

b
Force on electron= $q\left( {\vec v \times \vec B} \right) = e\left( {\vec B \times \vec v} \right)$

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