Find the number of photon emitted per minute by 60 what lamp of monochromatic light of wavelength `5000 overset @A`

Find the number of photons emitted per second by a 25 W source of monochromatic light of wavelength 6000 oversetcircA .

Estimating the following two numbers should be interesting. The first number will tell you why radio engineering do not need to worry much about photons. The second number tells you why our eye can never count photons, even in barely detetable light. The number of photons emitted per second by a MW transmitter of 10 kW power emitting radio waves of wavelength 500 m.

The two slits in Young's double slit experiment are seprated by a distance of 0.03 cm.When light of wavelength 5,000 overset@A falls on the slits,nd interference pattern is produced on the screen 1.5 m away.Find the distance of 4th bright fringe from the central maximum.

A beam of light consisting of two wavelegnths, 6,500 overset @A and 5,200 overset @A is used to obtain interfrerence fringes in a Young's double slit experirmejnt.The distance between the slits and the screen is 120 cm. Find the distance of third bright fringe on the screen from the central maximum for the wavelength 6,500 overset @A .

In Yound's double slit experiment,wer get 15 fringes per cm on the screen,while using light of wavelength 5,600 overset @A (sodium lamp).How many fringes per cm we get with ligth of wavelength 7,000 overset@A ?

A glass slab of thickness 4 cm contains the same number of waves as 5 cm of water,when both are traversed by the same monochromatic light.If the refractive index of water is 4//3 ,what is the refractive index of glass?

In a Young's double slit experiment,the fringe width obtained is 0.6 cm,when light of wavelength 4,800 overset @A is used .If the distance between the screen and the slit is reduced to half,what should be the wavelength of light used to obtain fringes 0.0045 m wide?