A leaser emits monochromatic radiation of wavelength 663 nm. If it emits 10^(5) quanta per second per square metre, calculate the power output of the laser in joule per square metre per second.

A leaser emits monochromatic radiation of wavelength 663 nm. If it emi

1.	A leaser emits monochromatic radiation of wavelength 663 nm. If it emits 10^(5) quanta per second per square metre, calculate the power output of the laser in joule per square metre per second.
Answer» Solution :ENERGY of one quantum `= hv = h (c)/(lamda) = ((6.63 xx 10^(-34)Js) (3 xx 10^(8) ms^(-1)))/((663 xx 10^(-9)m)) = 3 xx 10^(-19) J` Energy emitted per SEC per square metre = No. of quanta emitted per sq. metre per sec `xx` Energy of one quantum. `= 10^(15) xx 3 xx 10^(-19) J m^(-2) s^(-1)` `= 3xx 10^(-4) J m^(-2) s^(-1)`