Charge on electrons having total mass of 75 kg is ......C.

Options

A. `-1.32 xx 10^(13)`
B. `-6.25 xx 10^(18)`
C. `-1.25 xx 10^(13)`
D. `-1.6 xx 10^(19)`

Answer

A

Explanation

Mass M = `m_(e)n` where `m_(e) = 9.1 xx 10^(-31)` kg
`therefore n = M/m_(e) = 75/(9.1 xx 10^(-31))`
`therefore n=8.24 xx 10^(31)`
And electric charge
Q = ne
`=8.24 xx 10^(31) xx (-1.6 xx 10^(-19))`
`=-13.184 xx 10^(12)`
`=-13.2 xx 10^(13)` C