Explain electric field and its source as well as magnetic field and its source.
Explain electric field and its source as well as magnetic field and its source.
Source of electric field is charge.
If $Q$ charge is static, then electric field produce around it is,
$\overrightarrow{\mathrm{E}}=\frac{k Q}{r^{2}} \cdot \hat{r} \text { or } \overrightarrow{\mathrm{E}}=\frac{Q \hat{r}}{4 \pi \epsilon_{0} r^{2}}$
where $\hat{r}$ is unit vector of position vector $\vec{r}$ and $\vec{E}$ is electric field which is vector. Force on charge particle in electric field is given by
$\overrightarrow{\mathrm{F}} =q \overrightarrow{\mathrm{E}}$
$=\frac{k \mathrm{Q} q}{r^{2}} \hat{r} \text { or } \frac{\mathrm{Q} q}{4 \pi \in_{0} r^{2}} \cdot \hat{r}$
It can convey energy and momentum and is not established instantaneously but takes finite time to propagate.
It depending on each point in space, it can also vary with time. i.e. be a function of time.
In this chapter, we will assume that the fields do not change with time.
The field at a particular point can be due to one or more charges. If there are more charges the fields add vectorially. This is called the principle of superposition.
The force on a test charge is given by $\overrightarrow{\mathrm{F}}=\overrightarrow{\mathrm{E}} q_{0}$ where $q_{0}$ is known as test charge.
Static charges produces an electric field and moving charges produce electric field and magnetic field in addition which is denoted by $\overrightarrow{\mathrm{B}}(\vec{r})$.
Magnetic field is a vector quantity and it is defined at each point in space and it depend on time.
The magnetic field of several sources is the vector addition of magnetic field of each individual source. It obey the superposition principle.
Similar Questions
An electron is allowed to move with constant velocity along the axis of current carrying straight solenoid.
$A.$ The electron will experience magnetic force along the axis of the solenoid.
$B.$ The electron will not experience magnetic force.
$C.$ The electron will continue to move along the axis of the solenoid.
$D.$ The electron will be accelerated along the axis of the solenoid.
$E.$ The electron will follow parabolic path-inside the solenoid.
Choose the correct answer from the options given below:
An electron is allowed to move with constant velocity along the axis of current carrying straight solenoid.
$A.$ The electron will experience magnetic force along the axis of the solenoid.
$B.$ The electron will not experience magnetic force.
$C.$ The electron will continue to move along the axis of the solenoid.
$D.$ The electron will be accelerated along the axis of the solenoid.
$E.$ The electron will follow parabolic path-inside the solenoid.
Choose the correct answer from the options given below:
- [JEE MAIN 2023]
A metallic block carrying current $I$ is subjected to a uniform magnetic induction $\overrightarrow B $ as shown in the figure. The moving charges experience a force $\overrightarrow F $ given by ........... which results in the lowering of the potential of the face ........ Assume the speed of the carriers to be $v$
A metallic block carrying current $I$ is subjected to a uniform magnetic induction $\overrightarrow B $ as shown in the figure. The moving charges experience a force $\overrightarrow F $ given by ........... which results in the lowering of the potential of the face ........ Assume the speed of the carriers to be $v$
- [IIT 1996]
Answer the following questions:
$(a)$ A magnetic field that varies in magnitude from point to point but has a constant direction (east to west) is set up in a chamber. A charged particle enters the chamber and travels undeflected along a straight path with constant speed. What can you say about the initial velocity of the particle?
$(b)$ A charged particle enters an environment of a strong and non-uniform magnetic field varying from point to point both in magnitude and direction, and comes out of it following a complicated trajectory. Would its final speed equal the initial speed if it suffered no collisions with the environment?
$(c)$ An electron travelling west to east enters a chamber having a uniform electrostatic field in north to south direction. Specify the direction in which a uniform magnetic field should be set up to prevent the electron from deflecting from its straight line path.
Answer the following questions:
$(a)$ A magnetic field that varies in magnitude from point to point but has a constant direction (east to west) is set up in a chamber. A charged particle enters the chamber and travels undeflected along a straight path with constant speed. What can you say about the initial velocity of the particle?
$(b)$ A charged particle enters an environment of a strong and non-uniform magnetic field varying from point to point both in magnitude and direction, and comes out of it following a complicated trajectory. Would its final speed equal the initial speed if it suffered no collisions with the environment?
$(c)$ An electron travelling west to east enters a chamber having a uniform electrostatic field in north to south direction. Specify the direction in which a uniform magnetic field should be set up to prevent the electron from deflecting from its straight line path.
An ionized gas contains both positive and negative ions. If it is subjected simultaneously to an electric field along the $+x$ direction and a magnetic field along the $+z$ direction, then
An ionized gas contains both positive and negative ions. If it is subjected simultaneously to an electric field along the $+x$ direction and a magnetic field along the $+z$ direction, then
- [IIT 2000]
What is Lorentz force ? Write an expression for it
What is Lorentz force ? Write an expression for it