Answers (A Beka)
A brass rod has a cross-sectional area of 0.15 m2 at exactly 25°C. What is its area at
60.°C (α for brass ≈ 1.9 × 10-5/°C)? Ignore significant figures. - ANSWER-0.1501995m²
A certain glass has a refractive index of 1.66 for yellow light. What is the speed of
yellow light in this glass? - ANSWER-1.81×10⁸m/s
A concave mirror has a focal length of 30.0 cm. An object is placed 15.0 cm from the
mirror. What is (a) the radius of curvature of the mirror, (b) the image distance, and (c)
the lateral magnification of the image? - ANSWER-(a) r ≈ 60.0cm
(b) d_1 ≈ -30.0cm
(c) M ≈ 2.00
A converging lens has a focal length of 4.0 cm. An object is placed 5.0 cm in front of the
lens. Find the image distance. - ANSWER-20.cm
(the decimal is necessary for it to be 2 significant digits)
A light ray passing from a medium of high optical density to a medium of low optical
density will be ? . - ANSWER-bent away from the normal
A light ray traveling through air strikes the surface of a diamond whose refractive index
is 2.42. What is the angle of refraction if the angle of incidence is 20.0°? - ANSWER-
8.13°
A mirror with its reflecting side on the inside of a spherical surface is said to be a ?
mirror. - ANSWER-concave
A ray coming to a double convex lens along a path parallel to the principal axis is
redirected through the principal focal point. - ANSWER-true
A ray crosses a boundary between media, without bending, and travels through a new
media. - ANSWER-transmitted
A ray strikes a particle of a medium and bounces off in multiple directions. - ANSWER-
scattered
A surface that is optically flat has no irregularities with a height or depth exceeding a
half wavelength of light. - ANSWER-quarter
A(n) monochromatic lens is used to correct chromatic aberration. - ANSWER-
achromatic