Question:
The work done by an uniform magnetic field, on a moving charge is
The work done by an uniform magnetic field, on a moving charge is
Updated On: Apr 21, 2024
- zero because $\vec{F}$ acts parallel to $\vec{v}$
- positive because $\vec{F}$ acts perpendicular to $\vec{v}$
- zero because $\vec{F}$ acts perpendicular to $\vec{v}$
- negative because $\vec{F}$ acts parallel to $\vec{v}$
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The Correct Option is C
Solution and Explanation
Force on moving charge while moving in magnetic field is; $\vec{F}=q\left(\vec{v}\times\vec{B} \right)$ where $\vec{F}$ is perpendicular to $\vec{v}$
Work done/sec $=\vec{F},\vec{v}=Fv\,cos\,90�=0$
Work done/sec $=\vec{F},\vec{v}=Fv\,cos\,90�=0$
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Concepts Used:
Magnetic Field
The magnetic field is a field created by moving electric charges. It is a force field that exerts a force on materials such as iron when they are placed in its vicinity. Magnetic fields do not require a medium to propagate; they can even propagate in a vacuum. Magnetic field also referred to as a vector field, describes the magnetic influence on moving electric charges, magnetic materials, and electric currents.
A magnetic field can be presented in two ways.
- Magnetic Field Vector: The magnetic field is described mathematically as a vector field. This vector field can be plotted directly as a set of many vectors drawn on a grid. Each vector points in the direction that a compass would point and has length dependent on the strength of the magnetic force.
- Magnetic Field Lines: An alternative way to represent the information contained within a vector field is with the use of field lines. Here we dispense with the grid pattern and connect the vectors with smooth lines.
Properties of Magnetic Field Lines
- Magnetic field lines never cross each other
- The density of the field lines indicates the strength of the field
- Magnetic field lines always make closed-loops
- Magnetic field lines always emerge or start from the north pole and terminate at the south pole.