A problem of practical interest is to make a beam of electrons turn at $90^o$ corner. This can be done with the electric field present between the parallel plates as shown in the figure. An electron with kinetic energy $8.0 × 10^{-17}\ J$ enters through a small hole in the bottom plate. The strength of electric field that is needed if the electron is to emerge from an exit hole $1.0\ cm$ away from the entrance hole, traveling at right angles to its original direction is $y × 10^5\ N/C$ . The value of $y$ is
$4$
$8$
$10$
$1$
The escape speed of an electron launched from the surface of a glass sphere of diameter $1\ cm$ that has been charged to $10\ nC$ is $x \times 10^7\ m/sec$ . The value of $x$ is
A block of mass $m$ containing a net negative charge $-q$ is placed on a frictionless horizontal table and is connected to a wall through an unstretched spring of spring constant $k$ as shown. If horizontal electric field $E$ parallel to the spring is switched on, then the maximum compression of the spring is :-
In the following diagram the work done in moving a point charge from point $P$ to point $A, B$ and $C$ is respectively as $W_A,\, W_B$ and $W_C$, then (there is no charge nearby)
Four identical charges $ + \,50\,\mu C$ each are placed, one at each corner of a square of side $2\,m$. How much external energy is required to bring another charge of $ + \,50\,\mu C$ from infinity to the centre of the square......$J$ $\left( {{\rm{Given}}\frac{{\rm{1}}}{{{\rm{4}}\pi {\varepsilon _{\rm{0}}}}} = 9 \times {{10}^9}\,\frac{{N{m^2}}}{{{C^2}}}} \right)$
If one of the two electrons of a $H _{2}$ molecule is removed, we get a hydrogen molecular ion $H _{2}^{+}$. In the ground state of an $H _{2}^{+}$, the two protons are separated by roughly $1.5\;\mathring A,$ and the electron is roughly $1 \;\mathring A$ from each proton. Determine the potential energy of the system. Specify your choice of the zero of potential energy.