Question

The energy stored in a 60 cm length of a laser beam operating at 4 mW is

• A. $8\times {10}^{-12}J$
• B. $8\times {10}^{-14}J$
• C. $12\times {10}^{-12}J$
• D. $8\times {10}^{-14}J$

Answer 1

The correct option is A $8\times {10}^{-12}J$

$E=pt$ and $Sct$