You visited us 114 times! Enjoying our articles? Unlock Full Access!

Electric Field

In a certain ...

Question

In a certain region, uniform electric field $\to E = - E_{0}^k$ and uniform magnetic field $\to B = - B_{0}^k$ are present. At time $t = 0$ , a particle of mass $m$ and charge $q$ is given a velocity $v = v_{0}^j + v_{0}^k$ . Find the time when the speed of the particle is minimum.

\frac{4 m v_{0}}{q E_{0}}

No worries! We‘ve got your back. Try BYJU‘S free classes today!

\frac{3 m v_{0}}{q E_{0}}

No worries! We‘ve got your back. Try BYJU‘S free classes today!

\frac{2 m v_{0}}{q E_{0}}

No worries! We‘ve got your back. Try BYJU‘S free classes today!

\frac{m v_{0}}{q E_{0}}

Right on! Give the BNAT exam to get a 100% scholarship for BYJUS courses

Open in App

Solution

The correct option is D $\frac{m v_{0}}{q E_{0}}$
Given,
Electric field $\to E = - E_{0}^k$ ,
Magnetic field $\to B = - B_{0}^k$ ,
Velocity $v = v_{0}^j + v_{0}^k$ .

The acceleration of the particle,

$_{E} = \frac{q E_{0}}{m}$ (along $- v e$ z-direction)

Electric field will make z-component of velocity zero.

At that time, the speed of the particle will be minimum and that minimum speed is due to the other component ,i.e, y-component.

This is minimum when,

$v_{z} = u_{z} + a_{z} t$

$\Rightarrow 0 = v_{0} - \frac{q E_{0}}{m} t$

$∴ t = \frac{m v_{0}}{q E_{0}}$

Hence, option (d) is the correct answer.

Suggest Corrections

Similar questions

Q. In a certain region, uniform electron field

\to E = E_{0} (-^k)

and magnetic field

\to B = B_{0}^k

are present. At time

t = 0

, a particle of mass

m

and charge

q

is given a velocity

v_{0}^j + v_{0}^k

. The time, when the speed of particle is minimum will be:

Q. In a certain region uniform electric field

\to E = - E_{o}^k

and magnetic field

\to B = B_{o}^k

are present. At time t=0 a particle of mass m and charge q is given a velocity

\to v = v_{o}^j + v_{o}^k

.Find the minimum speed of the particle and the time when it happens so.

Q. In a certain region uniform electric field

\to E

and uniform magnetic field

\to B

are present in opposite directions. A particle of mass

m

and of charge

q

enters in this region with a velocity

v

at an angle

θ

from the magnetic field. The time after which the speed of the particle would be minimum is equal to :

Q. In a certain region there exist a uniform electric field

\to E

and a uniform magnetic field

\to B

both directed along z-axis. A particle of charge

Q

and mass

m

is projected at time

t = 0

with a velocity

v_{0}

along

x

-axis. Find the velocity at any instant of time

t

Q. A proton is fired from origin with velocity

\to v = v_{0}^j + v_{0}^k

in a uniform magnetic field

\to B = B_{0}^j

(Take

m =

mass and

q =

charge). Path of the proton particle is

Join BYJU'S Learning Program

Explore more

Electric Field

Standard XII Physics

Join BYJU'S Learning Program

In a certain region, uniform electric field →E=−E0^k and uniform magnetic field →B=−B0^k are present. At time t=0, a particle of mass m and charge q is given a velocity v=v0^j+v0^k. Find the time when the speed of the particle is minimum.

In a certain region, uniform electric field $\to E = - E_{0}^k$ and uniform magnetic field $\to B = - B_{0}^k$ are present. At time $t = 0$ , a particle of mass $m$ and charge $q$ is given a velocity $v = v_{0}^j + v_{0}^k$ . Find the time when the speed of the particle is minimum.