• Subject:

...

• Topic:

...

Monochromatic light of wavelength 667 nm is produced by a helium neon laser. The power emitted is 9mW. The number of photons arriving per second on the average at a target irradiated by this beam is

(a) $9×{10}^{17}$

(b) $3×{10}^{16}$

(c) $9×{10}^{15}$

(d) $3×{10}^{19}$

NEET