Question

Which of the following statements best describes the optical element hidden by the black box in the diagram given the behavior of the parallel rays of light incident on it? A) The black box must contain a concave lens. B) The black box must contain a convex lens. C) The black box must contain a flat piece of glass. D) The black box must contain a concave mirror. E) The black box must contain a convex mirror. Which of the following wavelengths of light is not visible to the average human eye? A) 475 nm B) 533 nm C) 644 nm D) 700 nm E) 810 nm Which type of wave is an electromagnetic wave? A) transverse B) sound C) longitudinal D) None of these. For a particular mirror with an object in front of it, the image distance is negative and half the object distance (positive) in magnitude. What can be said of the image? A) It is real, upright and smaller than the object. B) It is virtual, upright and smaller than the object. C) It is real, inserted and smaller than the object. D) It is virtual, inserted and bigger than the object. E) It is real, upright and bigger than the object. Which of the rays labeled in the diagram to the right would likely correspond to visible light that is red? A) B) C) D) E) F) G)

Answer 1

3.1 Ans. is (C)

3.2 Ans. is (E)

3.3 Ans. is (A)

3.4 Ans. is (B): When the image distance is negative, the image is behind the mirror, so the image is virtual.

3.5 Ans. is (A) : Since red has longest wavelength and hence counters lesser refractive index.

Hope this helps.