Home
Class 12
PHYSICS
In uniform magnetic field, if angle betw...

In uniform magnetic field, if angle between `vec(v) and vec(B) is 0^(@) lt 0 lt 90^(@)`, the path of particle is helix. Let `v_(1)` be the component of `vec(v) along vec(B) and v_(2)` be the component perpendicular to `vec(B)`. Suppose p is the pitch. T is the time period and r is the radius of helix. Then
`T = (2pim)/(qB), r = (mv_(2))/(qB), P = (v_(1))T`
Assume a charged particle of charge q and mass m is released from the origin with velocity `vec(v) = v_(0) hat(i) - v_(0) hat(k)` in a uniform magnetic field `vec(B) = -B_(0) hat(k)`.
Angle between v and B is

A

`45^(@)`

B

`30^(@)`

C

`60^(@)`

D

`120^(@)`

Text Solution

Verified by Experts

The correct Answer is:
A
`vec(v)*vec(B)=|v||B| cos theta`
or `cos theta =(vec(v)*vec(B))/(|v||B|)=(B_(0)v_(0))/(sqrt(2)v_(0)B_(0))=(1)/(sqrt(2))`
or `theta=45^(@)`
Hence choice (a) is correct.
Doubtnut Promotions Banner Mobile Dark
|

Topper's Solved these Questions

  • MISCELLANEOUS VOLUME 5

    CENGAGE PHYSICS|Exercise Integer|12 Videos

  • MISCELLANEOUS VOLUME 5

    CENGAGE PHYSICS|Exercise Multiple Correct|34 Videos

  • MISCELLANEOUS VOLUME 3

    CENGAGE PHYSICS|Exercise True and False|3 Videos

  • Moving charges and magnetism

    CENGAGE PHYSICS|Exercise Question Bank|20 Videos

Similar Questions

Explore conceptually related problems

A particle of specific charge 'alpha' is projected from origin at t=0 with a velocity vec(V)=V_(0) (hat(i)-hat(k)) in a magnetic field vec(B)= -B_(0)hat(k) . Then : (Mass of particle =1 unit)

What is the direction of the force acting on a charged particle q, moving with a velocity vec(v) a uniform magnetic field vec(B) ?

Knowledge Check

  • In uniform magnetic field, if angle between vec(v) and vec(B) is 0^(@) lt 0 lt 90^(@) , the path of particle is helix. Let v_(1) be the component of vec(v) along vec(B) and v_(2) be the component perpendicular to vec(B) . Suppose p is the pitch. T is the time period and r is the radius of helix. Then T = (2pim)/(qB), r = (mv_(2))/(qB), P = (v_(1))T Assume a charged particle of charge q and mass m is released from the origin with velocity vec(v) = v_(0) hat(i) - v_(0) hat(k) in a uniform magnetic field vec(B) = -B_(0) hat(k) . Axis of helix is along

    A
    X-axis
    B
    Y-axis
    C
    Negative Y-axis
    D
    Z-axis

  • In uniform magnetic field, if angle between vec(v) and vec(B) is 0^(@) lt 0 lt 90^(@) , the path of particle is helix. Let v_(1) be the component of vec(v) along vec(B) and v_(2) be the component perpendicular to vec(B) . Suppose p is the pitch. T is the time period and r is the radius of helix. Then T = (2pim)/(qB), r = (mv_(2))/(qB), P = (v_(1))T Assume a charged particle of charge q and mass m is released from the origin with velocity vec(v) = v_(0) hat(i) - v_(0) hat(k) in a uniform magnetic field vec(B) = -B_(0) hat(k) . Pitch of helical path described by particle is

    A
    `(2mv_(0))/(qB_(0))`
    B
    `(2pimv_(0))/(qB_(0))`
    C
    `(sqrt(2)pimv_(0))/(qB_(0))`
    D
    `(sqrt(3)pimv_(0))/(qB_(0))`

  • A portion is fired from origin with velocity vec(v) = v_(0) hat(j)+ v_(0) hat(k) in a uniform magnetic field vec(B) = B_(0) hat(j) . In the subsequent motion of the proton

    A
    its z co-ordinate can never be negative
    B
    its x co-ordinate can never be positive
    C
    its x and z co-oridinate cannot be zero at the same time
    D
    its y co-ordinate will be proportional to its time of flight

    • Similar Questions

    Explore conceptually related problems

    What is the angle between the v ectprs (vec A xx vec B) and (vec Bxx vec A) ?

    A charged particle of specific charge (charge/mass) alpha released from origin at time t=0 with velocity vec v = v_0 (hat i + hat j) in uniform magnetic field vec B = B_0 hat i. Coordinates of the particle at time t= pi//(B_0 alpha) are

    If two bodies are in motion with velocity vec(v)_(1) and vec(v)_(2) :

    A charge particle moves with velocity vec(V) in a uniform magnetic field vec(B) . The magnetic force experienced by the particle is

    A particle of charge q and mass m starts moving from the origin under the action of an electric field vec E = E_0 hat i and vec B = B_0 hat i with a velocity vec v = v_0 hat j . The speed of the particle will become 2v_0 after a time.

    Home
    Profile