Tag: charge

Charge on a body is always $\displaystyle \pm e$, $\displaystyle \pm 2e$, $\displaystyle \pm 3e$. It can never be in fraction of e. i.e. 1.5e or -1.2e.

Since the charge is placed at the centre of the cube, so the electric flux lines move out equally from all sides of the cube. Thus the electric flux emerging from the cube is equal to $\dfrac{q}{\varepsilon _0}$.

Photon is the elementary quantum of energy.

Bulbs in street lightning are all connected in parallel.

For testing appliances, the wattage of test lamp should be high, as higher watt lamps have lower resistance and will not blow up the testing appliacnces.

The additive nature of charge is one of the property of electric charge. The entire electric charge of a system is equal to the algebraic sum of electric charges located in the system. This is the law of superimposition of electric charge.

As charge is quantized. 

Total charge must be quantized i.e., it must be a multiple of charge of $e^-$ $=$ $1\cdot 6\times 10^{-19}C$
as $4\times (1\cdot 6\times 10^{-19})=6\cdot 4\times 10^{-19}$
this charge is possible ($4e^-$)

We know that charge must be integral multiples of $1\cdot 6\times 10^{-19}C$ as charge of
one electron $=1\cdot 6\times 10^{-19}C$
We cannot get any charge less than $1\cdot 6\times 10^{-19}$  $\therefore$ we cannot get $9\cdot 6\times 10^{-20}C$

The charges from one body can be transferred to another body but the total charge of a system remains constant.