Prakash bought an electric bulb which is rated as 70 W . He knows the fact that a 70 W bulb consumes 70 joules of electrical energy per second .
The energy consumed by it per second is `"______"`ergs.

Options

A. 700
B. `70 xx 10^(7)`
C. `7 xx 10^(7)`
D. `70 xx 10^(5)`

Answer

B

Explanation

70 joule = 70 newton meters = `70 xx 10^(5)` dynes `xx` 100 cm = `70 xx 10^(7)` dyne cm
Therefore, 70 joules `= 70 xx 10^(7)` erg
Hence, the correct option is (b).