Home
Class 12
PHYSICS
A electron experiences a force (4.0hati ...

A electron experiences a force `(4.0hati +3.0hatj) xx 10^(-13)N` in a uniform magnetic field when its velocity is `2.5hak xx 10^(7)ms^(-1)` When the velocity is redirected and becomes `(1.5hati - 2.0hatj)xx10^(7) xx 10^(-7)` the magnetic force of the electron is zero. The magnetic field vectro `oversetrarr(B)` is .

A

`-0.075hati+0.1hatj`

B

`0.1hati+0.075hatj`

C

`0.075hati-0.1hatj +hatk`

D

`0.075 hatj -0.1hatj`

Text Solution

Verified by Experts

The correct Answer is:
A
`oversetrarr(F_(m))=q (oversetrarrV xx oversetrarrB) = - e (oversetrarrV xx oversetrarrB) = e (oversetrarrB xx oversetrarrV)`
`(4hati xx 3hatj) xx 10^(-13)`
` = 16 xx 10^(-19) (B_(x) hati + B_(y) hatj) xx 2.5 xx 10^(7) hatk`
`(4hati + 3hatj) = (40B_(y) hati - 40B_(x)hatj)`
`oversetrarr(B) = - 0.075 hati + 0.1 hatj ` .
Promotional Banner

Similar Questions

Explore conceptually related problems

A magnetic field of 8hatkmT exerts a force of (4.0hati+3.0hatj)xx10^(-10)N on a particle having a charge of 5xx10^(-10)C and going in the X-Y plane.Find the velocity of the particle.

A bar magnet lies in a magnetic field of intensity 0.5 xx 10^(-4) tesla. The torque required to deflect it through 30^(@) is 2.5 xx 10^(-5)N m . Calculate the magnetic moment of the magnet.

An electron files into a homogeneous magnetic field of 10 ^(-3) perpendicular to the force lines. The velocity of the electron is v = 4 xx 10 ^(7)ms ^(-1) what is the tangential acceleration of electron in the magnetic field ?

An electron of velocity 2.652 xx 10^(7) m/s enters a uniform magnetic field of direction of motion . The radius of its path is

An electron is emittied with a veloctiy of 5 xx 10 ^(6) ms^(-1) . It is accelerated by an electric field in the direction of initial velocity at 3xx 10^(14) ms^(-2) . If its final velocity is 7xx10^(6) ms^(-1) calculation the distance coverd by the electron .

An alpha particle is moving with a velocity of (7 xx 10^(5) hat i m//s) in a magnetic field of (5 hat i + 9 hat j ) . T . Find the magnetic force acting on the particle.

An electron experiences a magnetic force of magnitude 4.60 xx 10^-15 N , when moving at an angle of 60^@ with respect to a magnetic field of magnitude 3.50 xx 10^-3 T . Find the speed of the electron.

A proton enters a magnetic field with a velocity of 2.5 xx10^(7)ms^(-1) making an angle 30^(@) with the magnetic field. The force on the proton is (B=25T)

calculate the force experinced by an electron when it enters a uniform magnetic field of strength 2 T with vleocity 0.2 xx 10^(8) m s^(-1) at right angles to the field. What kind of motion will it have in the magnetic field ? (Charge of electron 1.6 xx 10^(-19) coulomb.)