A charged particle with charge  q enters a region of constant, uniform and mutually orthogonal fields \vec{E}\; and \; \vec{B}  with a velocity

\vec{v} perpendicular to both \vec{E}\; and \; \vec{B} , and comes out without any change in magnitude or direction of \vec{v}. Then

  • Option 1)

    \vec{v}=\vec{B}\times \vec{E}/E^{2}

  • Option 2)

    \vec{v}=\vec{E}\times \vec{B}/B^{2}

  • Option 3)

    \vec{v}=\vec{B}\times \vec{E}/B^{2}

  • Option 4)

    \vec{v}=\vec{E}\times \vec{B}/E^{2}

 

Answers (1)

As we learnt in

Magnetic field If V(vector), E (vector) and B (vector) are mutually perpendicular -

Fe=Fm

V=\frac{E}{B}

-

 

 

 

When \vec{E}\; and \; \vec{B} are perpendicular and velocity has no changes then qE=qvB\, \, i.e.,\: v=\frac{E}{B}.  The two forces oppose each other if v  is along  \vec{E}\times \vec{B}  i.e.,

\vec{v}=\frac{\vec{E}\times \vec{B}}{B^{2}}

As \vec{E}\; and \; \vec{B}   are perpendicular to each other

\frac{\vec{E}\times \vec{B}}{B^{2}}=\frac{EB\, sin\, 90^{0}}{B^{2}}=\frac{E}{B}

 


Option 1)

\vec{v}=\vec{B}\times \vec{E}/E^{2}

Incorrect option

Option 2)

\vec{v}=\vec{E}\times \vec{B}/B^{2}

Correct option

Option 3)

\vec{v}=\vec{B}\times \vec{E}/B^{2}

Incorrect option

Option 4)

\vec{v}=\vec{E}\times \vec{B}/E^{2}

Incorrect option

Most Viewed Questions

Preparation Products

Knockout JEE Main April 2021 (One Month)

Personalized AI Tutor and Adaptive Time Table, Self Study Material, Weekend Live Classes, Unlimited Mock Tests and Personalized Analysis Reports, 24x7 Doubt Chat Support,.

₹ 14000/- ₹ 4999/-
Buy Now
Knockout JEE Main May 2021

Personalized AI Tutor and Adaptive Time Table, Self Study Material, Weekend Live Classes, Unlimited Mock Tests and Personalized Analysis Reports, 24x7 Doubt Chat Support,.

₹ 22999/- ₹ 9999/-
Buy Now
Test Series JEE Main May 2021

Unlimited Chapter Wise Tests, Unlimited Subject Wise Tests, Unlimited Full Mock Tests, Get Personalized Performance Analysis Report,.

₹ 6999/- ₹ 2999/-
Buy Now
Knockout JEE Main May 2022

Personalized AI Tutor and Adaptive Time Table, Self Study Material, Live Classes, Unlimited Mock Tests and Personalized Analysis Reports, 24x7 Doubt Chat Support,.

₹ 34999/- ₹ 24999/-
Buy Now
JEE Main Rank Booster 2021

Booster and Kadha Video Lectures, Unlimited Full Mock Test, Adaptive Time Table, 24x7 Doubt Chat Support,.

₹ 13999/- ₹ 6999/-
Buy Now
Boost your Preparation for JEE Main 2021 with Personlized Coaching
 
Exams
Articles
Questions