Question

A charged particle is moving along positive y-axis in uniform electric and magnetic fields
$\overrightarrow{E}=E_o\hat{k}$ and $\overrightarrow{B}=B_o\hat{i}$

Here $E_o$ and $B_o$ are positive constants.Choose the correct options.

• A. particle may be deflected towards positive z-axis
• B. particle may be deflected towards negative z-axis
• C. particle may pass undeflected
• D. kinetic energy of particle may remain constant

Answer 1

Answer: (A), (B), (C), (D)

The correct options are
A particle may be deflected towards positive z-axis
B particle may be deflected towards negative z-axis
C particle may pass undeflected
D kinetic energy of particle may remain constant

$\overrightarrow{F_m}=q(\overrightarrow{v}\times \overrightarrow{B})$
Depending on sign of q,$\overrightarrow{F_m}$,may be along positive z-axis or along negative z-axis.
$\overrightarrow{F_e}=q\overrightarrow{E}$
Again, depending on the value of q it may be along positive z-axis or along negative z-axis.
If q is positive,$\overrightarrow{v}\times \overrightarrow{B}$ and $\overrightarrow{F_m}$ comes along negative z-axis also.But $\overrightarrow{F_e}$ comes along posiive z-axis.So it may also pass undeflected.