Define magnetic flux density in terms of the force on a current-carrying conductor.
Electrons, each with mass $m$ and charge $q$, are accelerated from rest in a vacuum through a potential difference $V$. Derive an expression, in terms of $m$, $q$ and $V$, for their final speed $v$. Explain your working.
The accelerated electrons in (b) are introduced at point $S$ into a region of uniform magnetic field of flux density $B$, as shown in Fig. 8.1. The electrons travel at right angles to the direction of the magnetic field. Their path is a circle of radius $r$. Show that the specific charge $\frac{q}{m}$ of the electrons is given by the expression $\frac{q}{m} = \frac{2V}{B^2 r^2}$. Explain your working.
Electrons are accelerated through a potential difference $V$ of $230\,\text{V}$. The electrons are injected normally into the magnetic field of flux density $0.38\,\text{mT}$. The radius $r$ of the circular orbit of the electrons is $14\,\text{cm}$. Use this information to calculate a value for the specific charge of an electron.
Suggest why the arrangement outlined in (ii), using the same values of $B$ and $V$, is not practical for determining the specific charge of $\alpha$-particles.
Show that the specific charge $\frac{q}{m}$ of the electrons is given by the expression $\frac{q}{m} = \frac{2V}{B^2 r^2}$. Explain your working.
Electrons are accelerated through a potential difference $V$ of $230\,\text{V}$. The electrons are injected normally into the magnetic field of flux density $0.38\,\text{mT}$. The radius $r$ of the circular orbit of the electrons is $14\,\text{cm}$. Use this information to calculate a value for the specific charge of an electron.
Suggest why the arrangement outlined in (ii), using the same values of $B$ and $V$, is not practical for determining the specific charge of $\alpha$-particles.