Ncert Exercises & Solutions

2.38 A certain particle carries 2.5 × 10–16C of static electric charge. Calculate the number of electrons present in it.

Charge on one electron = 1.6022 × $10^{- 19}$ C
⇒ 1.6022 × $10^{- 19}$ C charge is carried by 1 electron.
∴ Number of electrons carrying a charge of 2.5 × $10^{- 16}$ C

$= \frac{1}{1.6022 x 10^{- 19} C} (2.5 x 10^{- 16} C)$
$= 1.560 x 10^{3} C$
$= 1560 C$