- Home
- Standard 12
- Physics
4.Moving Charges and Magnetism
medium
The figure shows three situations when an electron moves with velocity $\vec v$ travels through a uniform magnetic field $\vec B$. 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, $+\,ve\,\,x-$ axis and zero
D
$-ve\,\,z-$ axis, $+ve\,\,x-$ axis and zero
Solution
$1.$ $\vec{F}_{m}=(-e)(-v \hat{i} \times B \hat{j})=-$Bev $\hat{k}$ i.e. $-z$ $-axis$
$2.$ $\vec{F}_{m}=(-e)(-v \hat{j} \times B \hat{k})=-$Bev$\hat{i}$ ie. $-x$ $-axis$
$3.$ $\vec{F}_{m}=(-e)(-v \hat{j} \times B \hat{k})=0$
Alternatively, use Fleming's left hand rule.
Standard 12
Physics
Similar Questions
medium
normal
