Question

1erg is equal to:

• A. 1 Nm
• B. ${10}^{-7}J$
• C. $1gcm{s}^{-2}$
• D. ${10}^{7}J$

Answer 1

Answer: (B)

An erg is the amount of work done by a force of one dyne exerted for a distance of one centimeter. In the CGS base units, it is equal to one gram centimeter-squared per second-squared

And joule is SI unit of work done or energy equals work done by force of 1N for a displacement of 1m.

So converting cgs to SI unit.

$1erg={10}^{-3}N\times ({10}^{-2}m{)}^2\times 1s$ $={10}^{-7}$J.