CBSE 12TH PHYSICS - Online Test
The triboelectric effect (also known as triboelectric charging) is a type of contact electrification in which certain materials become electrically charged after they come into frictional contact with a different material. Rubbing glass with fur, or a plastic comb through the hair, can build up triboelectricity.
When we charge something with static electricity, no electrons are made or destroyed. No new protons appear or disappear. Electrons are just moved from one place to another. The net, or total, electric charge stays the same. This is called the principle of conservation of charge.
If a glass rod is rubbed with silk, some electrons moves from glass rod to silk no new charge is generated or destroyed.
As in the case with DC power, the instantaneous electric power in an AC circuit is given by P = VI, but these quantities are continuously varying. So the average power is given by
Pavg = VI cosφ
where φ is the phase angle between the current and the voltage and where V and I are understood to be the effective or rms values of the voltage and current.
Now RMS value of I is =
So, RMS value of V=
Therefore, Power will be
P= (because cosφ= 1 for circuit containing resistance only)
The internal resistance of the cell is given by:
