Q: A charge q is moving with a velocity v parallel to a magnetic field B. Force on the charge due to magnetic field is

\$ F + q(\vec{V}\times \vec{B})\$\$\overrightarrow{V}||\overrightarrow{B},\theta=0\$\$F=0\$

Q: The following cases in which no force is exerted by a magnetic field on a charge is

\$F_B=q(\overrightarrow{v}\times \overrightarrow{B})\$if \$v=0, F_B=0\$

Q: A proton moving in a straight line enters a strong magnetic field along the field direction then its path and velocity will be

\$F = q (\vec{V}\times \vec{B})\$\$= q VB sin 0\$\$= q VB sin 0^0\$ \$(\because \text{V and B has same direction})\$\$= 0\$ \$(\because sin0^0 = 0)\$So, there is no force, so, path is same and velocity is constant.

Q: A proton is traveling due north. If a uniform magnetic field is applied vertically down then the particlea) deflected towards westb) revolves in anti clock wise directionc) acquires acceleration d) comes to rest

\$\vec{F} = q(\vec{V}\times \vec{B})\$So, \$\vec{V}\times \vec{B}\$ direction will be in west by right hand thumb rule. So, it will revolves in anti-clockwise direction and it acquires radial acceleration.

Q: A charge moving with velocity v in X - direction is subjected to a field of magnetic induction in the negative X direction. As a result the charge will

\$F = q (\vec{V}\times \vec{B})\$\$= q VB sin 0\$\$= q VB sin(180^0)\$ \$(\because\text { velocity is in X-direction and B is in -X-direction})\$\$= 0\$ \$(\because sin180^0 = 0)\$So, charge will be more unaffected.

Q: If an electron of velocity is \$2i+4j\$ is subjected to magnetic field of \$4k\$, then, for the electron ,

\$F = q(\vec{V}\times \vec{B})\$\$= e[(2i+4j)\times 4k]\$\$= e[-8j+16i]\$ (By cross-product rule)So, it has non-zero force, so it velocity direction changes so, path changes, velocity changes, momentum changes but magnitude of velocity is constant, so, speed remains constant.

Question 1

A charge q is moving with a velocity v parallel to a magnetic field B. Force on the charge due to magnetic field is

Accepted Answer

$ F + q(\vec{V}\times \vec{B})$$\overrightarrow{V}||\overrightarrow{B},\theta=0$$F=0$

Question 2

The following cases in which no force is exerted by a magnetic field on a charge is

Accepted Answer

$F_B=q(\overrightarrow{v}\times \overrightarrow{B})$if $v=0, F_B=0$

Question 3

The force acting on a charge q moving with a velocity V in a magnetic field of induction B is given by :

Accepted Answer

The magnetic force on a free moving charge is perpendicular to both the velocity of the charge and the magnetic field with direction given by the right hand rule . The force is given by the charge times the vector product of velocity and magnetic field.

Question 4

A proton moving in a straight line enters a strong magnetic field along the field direction then its path and velocity will be

Accepted Answer

$F = q (\vec{V}\times \vec{B})$$= q VB sin 0$$= q VB sin 0^0$        $(\because \text{V and B has same direction})$$= 0$                         $(\because sin0^0 = 0)$So, there is no force, so, path is same and velocity is constant.

Question 5

A proton is traveling due north. If a uniform magnetic field is applied vertically down then the particle
a) deflected towards west
b) revolves in anti clock wise direction
c) acquires acceleration
d) comes to rest

Accepted Answer

$\vec{F} = q(\vec{V}\times \vec{B})$So, $\vec{V}\times \vec{B}$ direction will be in west by right hand thumb rule. So, it will revolves in anti-clockwise direction and it acquires radial acceleration.

Question 6

A charged particle is projected perpendicular to a uniform magnetic field. Arrange the following in correct order of occurrence :
A) The direction of momentum of the particle changes
B) The particle experiences a force
C) The particle revolves in a circular path

Accepted Answer

When particle is projected in uniform magnetic field a force = $q(\vec{V}\times \vec{B})$ acts which result in change in direction of momentum of the particle and particle starts revolving in a circular path.So, order is B, A, C.

Question 7

A charge moving with velocity v in X - direction is subjected to a field of magnetic induction in the negative X direction. As a result the charge will

Accepted Answer

$F = q (\vec{V}\times \vec{B})$$= q VB sin 0$$= q VB sin(180^0)$       $(\because\text { velocity is in X-direction and B is in -X-direction})$$= 0$                      $(\because sin180^0 = 0)$So, charge will be more unaffected.

Question 8

If an electron of velocity is $2i+4j$ is subjected to magnetic field of $4k$, then, for the electron ,

Accepted Answer

$F = q(\vec{V}\times \vec{B})$$= e[(2i+4j)\times 4k]$$= e[-8j+16i]$          (By cross-product rule)So, it has non-zero force, so it velocity direction changes so, path changes, velocity changes, momentum changes but magnitude of velocity is constant, so, speed remains constant.

Question 9

A vertical straight conductor carries a current vertically upwards. A point $P$ lies to the east of it at a small distance and another point $Q$ lies to the west at the same distance the magnetic field at $P$ is :

Accepted Answer

As per Biot Savart Law, Magnetic field at a point is inversely proportional to square of distance from the current carrying conductor. Therefore magnitude of magnetic field is same at both points P and Q, irrespective of their position from the conductor.

Question 10

If a charged particle is projected perpendicular to a uniform magnetic field, thena) it revolves in circular pathb) its K.E. remains constantc) its momentum remains constantd) its path is spiral

Accepted Answer

If a charged particle is projected perpendicular to a uniform magnetic field, then
a) it revolves in circular path
b) its K.E. remains constant
c) its momentum remains constant
d) its path is spiral

A

only a, b are correct

B

only a, c are correct

C

only b, d are correct

D

only a, d are correct

Easy

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Moving Charges And Magnetism

Physics
6812 Views

A charge q is moving with a velocity v parallel to a magnetic field B. Force on the charge due to magnetic field is

The following cases in which no force is exerted by a magnetic field on a charge is

The force acting on a charge q moving with a velocity V in a magnetic field of induction B is given by :

A proton moving in a straight line enters a strong magnetic field along the field direction then its path and velocity will be

A proton is traveling due north. If a uniform magnetic field is applied vertically down then the particle
a) deflected towards west
b) revolves in anti clock wise direction
c) acquires acceleration
d) comes to rest

A charged particle is projected perpendicular to a uniform magnetic field. Arrange the following in correct order of occurrence :
A) The direction of momentum of the particle changes
B) The particle experiences a force
C) The particle revolves in a circular path

A charge moving with velocity v in X - direction is subjected to a field of magnetic induction in the negative X direction. As a result the charge will

If an electron of velocity is $2 i + 4 j$ is subjected to magnetic field of $4 k$ , then, for the electron ,

A vertical straight conductor carries a current vertically upwards. A point $P$ lies to the east of it at a small distance and another point $Q$ lies to the west at the same distance the magnetic field at $P$ is :

If a charged particle is projected perpendicular to a uniform magnetic field, then
a) it revolves in circular path
b) its K.E. remains constant
c) its momentum remains constant
d) its path is spiral

Moving Charges And Magnetism

Physics 6812 Views

A charge q is moving with a velocity v parallel to a magnetic field B. Force on the charge due to magnetic field is

The following cases in which no force is exerted by a magnetic field on a charge is

The force acting on a charge q moving with a velocity V in a magnetic field of induction B is given by :

A proton moving in a straight line enters a strong magnetic field along the field direction then its path and velocity will be

A proton is traveling due north. If a uniform magnetic field is applied vertically down then the particle a) deflected towards west b) revolves in anti clock wise direction c) acquires acceleration d) comes to rest

A charged particle is projected perpendicular to a uniform magnetic field. Arrange the following in correct order of occurrence : A) The direction of momentum of the particle changes B) The particle experiences a force C) The particle revolves in a circular path

A charge moving with velocity v in X - direction is subjected to a field of magnetic induction in the negative X direction. As a result the charge will

If an electron of velocity is 2i+4j is subjected to magnetic field of 4k, then, for the electron ,

A vertical straight conductor carries a current vertically upwards. A point P lies to the east of it at a small distance and another point Q lies to the west at the same distance the magnetic field at P is :

If a charged particle is projected perpendicular to a uniform magnetic field, then a) it revolves in circular path b) its K.E. remains constant c) its momentum remains constant d) its path is spiral

Physics
6812 Views

A proton is traveling due north. If a uniform magnetic field is applied vertically down then the particle
a) deflected towards west
b) revolves in anti clock wise direction
c) acquires acceleration
d) comes to rest

A charged particle is projected perpendicular to a uniform magnetic field. Arrange the following in correct order of occurrence :
A) The direction of momentum of the particle changes
B) The particle experiences a force
C) The particle revolves in a circular path

If an electron of velocity is $2 i + 4 j$ is subjected to magnetic field of $4 k$ , then, for the electron ,

A vertical straight conductor carries a current vertically upwards. A point $P$ lies to the east of it at a small distance and another point $Q$ lies to the west at the same distance the magnetic field at $P$ is :

If a charged particle is projected perpendicular to a uniform magnetic field, then
a) it revolves in circular path
b) its K.E. remains constant
c) its momentum remains constant
d) its path is spiral