Question

do the two questions

*Question 221: Microscope A crude symmetric hand held microscope consists of two converging lenses each of focal length 5.0 cm fastened in the ends of a tube 40 cm long. What is the overall angular magnification of the microscope? (Use a near point of 25 cm.) Select one: O a.-1 O b.-40 O C. -30 oo

Answer 1

Question 221: Microscope

The equation of the angular magnification for a microscope is given by the following equation:

me =

where fe is the focal length and q is the point near the eye. Angular amplification is a maximum when the image appears at the proximal point of the human eye, that is, when q=-25 cm.

-25cm me = 1 fe

and the focal length is 5 cm, substituting in the equation, you get:

me = -25cm me = 5cm Pom5

Question 235: Thin film interference

To determine the thickness of the film so that it does not reflect the light, we must use the equation that determines the Conditions for interference be destructive in thin film.

2nt =m

where n is the refractive index of the thin film, t is the thickness of the film and $\lambda$ is the wavelength. m is an integer that we will take as 1, m = 1. Solving the previous equation for thickness, we get:

t=m) _ (1)(600nm) - = 231nm 2n 2(1.30)