Aplano-convex glass lens of radius of curvature 1.8 m rests on an optically flat glass plate. the arrangement is illuminated from above with monochromatic light of 559-nm wavelength. the indexes of refraction of the lens and plate are 1.6. determine the radii of the first and second bright fringes in the reflected light.

0.000709 m

0.00122 m

Explanation:

R = Radius of curvature = 1.8 m

λ =  Wavelength = 559 nm = 559×10⁻⁹ m

Radius of bright fringe

First bright fringe means at m = 0

First second fringe means at m = 1

∴ Radius of the first bright fringe is 0.000709 m

∴ Radius of the second bright fringe is 0.00122 m

answer: the exterior temperature of commercial jet planes as they leave the stratosphere and return to the ground increases steadily.

explanation:

the lower most layer of atmosphere is troposphere which extends from 0 to 12 km above the surface of the earth. the temperature initially decreases as distance is increased from the earth's surface. commercial jets fly in lower part of the stratosphere. the stratosphere extends upto 50 km. the temperature in stratosphere starts rising again due to presence of ozone which traps the uv rays.

thus, when the planes leave the stratosphere and return to the ground, the exterior temperature increases steadily.

false.

explanation:

this statement is false. after falling for 5 seconds, its speed will not be 100 m/s.