A sphere of radius $1\,cm$ has potential of $8000\,V$, then energy density near its surface will be
$64 \times {10^5}\,J/{m^3}$
$8 \times {10^3}\,J/{m^3}$
$32\,J/{m^3}$
$2.83\,J/{m^3}$
A piece of cloud having area $25 \times {10^6}\,{m^2}$ and electric potential of ${10^5}$ $volts$. If the height of cloud is $0.75\,km$, then energy of electric field between earth and cloud will be.....$J$
In a uniform electric field, a cube of side $1\ cm$ is placed. The total energy stored in the cube is $8.85\mu J$ . The electric field is parallel to four of the faces of the cube. The electric flux through any one of the remaining two faces is.
If the plates of a parallel plate capacitor connected to a battery are moved close to each other, then
$A$. the charge stored in it, increases.
$B$. the energy stored in it, decreases.
$C$. its capacitance increases.
$D$. the ratio of charge to its potential remains the same.
$E$. the product of charge and voltage increases.
Choose the most appropriate answer from the options given below:
A $40$ $\mu F$ capacitor in a defibrillator is charged to $3000\,V$. The energy stored in the capacitor is sent through the patient during a pulse of duration $2\,ms$. The power delivered to the patient is......$kW$
A parallel plate capacitor has an electric field of ${10^5}\,V/m$ between the plates. If the charge on the capacitor plate is $1\,\mu \,C$, the force on each capacitor plate is......$N$