Moving Charges ...

Electron of mass m and charge q is travelling with a speed v along a circular path of radius r at right angles to a uniform magnetic field of intensity B. If the speed of the electron is doubled and the magnetic field is halved the resulting path would have a radius.

Three long straight wires A, B and C are carrying currents as shown in figure. Then the resultant force on B is directed :

A long curved conductor carrier a current $$\vec{I}$$($$\vec{I}$$ is a vector). A small current element of length $$d \vec l$$, on the wire, induces a magnetic field at a point, away from the current element. If the position vector between the current element and the point is $$\vec{r}$$, making an angle $$\theta$$ with current element then, the induced magnetic field density, $$d \vec B$$ at the point is $$(\mu_0=$$permeability of free space):

The direction of the force on a current carrying conductor held perpendicular to an uniform magnetic field is given by:

Match the following and find the correct pairs:

A point charged particle of mass $$2\times 10^{-4} kg$$ is moving perpendicular to the uniform magnetic field of magnitude 0.1-tesla.Calculate the acceleration of the particle due to the magnetic field if its velocity is $$3\times 10^4m/s$$ and its charge is $$+4.0\times 10^{-9}C$$.

The force a magnetic field exerts on an electron is largest when the path of the electron is oriented

An unknown particle is being studied in a magnetic field of variable intensity and direction. When the magnetic field is turned off, the particle is observed to move toward the earth. When the magnetic field is turned on, the particle is observed to continue to move toward the earth, no matter the strength or the direction of the magnetic field. Which of the particles listed below is most likely the unknown particle?

A cation enters in the uniform magnetic field region and moves in a semicircular path in the direction indicated in above figure. Identify the direction of the magnetic field?

The diagram above shows atomic particles moving through a magnetic field.
A beam of electrons is deflected in the magnetic field and strikes at the point $$P$$ as shown in the figure.
At which letter would a stream of electrons strike the screen if the poles of the magnet were reversed?