Energy failing per aqure metre per second is .Number of quanta falling per metre second xx Energy of one question
`= 6.37 xx 10^(15) xx (hc)/(lambda)`
`= 6.37 xx 10^(12) xx (6.25 xx 10^(-34) xx 3 xx 10^(8))/(632.6 xx 10^(-6))`
`= 2 xx 10^(-3) J m^(-1)s^(-1)`