Images Formed by Lenses AP Physics 2 MCQ – Exam Style Questions etc.
Images Formed by Lenses AP Physics 2 MCQ
Unit 13: Geometric and Physical Optics
Weightage : 15–18%
Exam Style Practice Questions , Images Formed by Lenses AP Physics 2 MCQ
Question
An object is placed at a distance of 1.5f from a converging lens of focal length f, as shown. What type of image is formed and what is its size relative to the object?
Type Size
(A) Virtual Larger
(B) Virtual Same size
(C) Real Smaller
(D) Real Larger
Answer/Explanation
Ans: D
Solution: Draw the ray diagram, or makeup some numbers and do the math.
Question
A narrow beam of monochromatic light enters a lens parallel to the optic axis, as shown in the accompanying diagram. Which arrow best represents the direction of the light after leaving the lens?
(A) arrow A (B) arrow B
(C) arrow D (D) arrow E
Answer/Explanation
Ans: D
Solution: A horizontal beam approaching a converging lens bends and converges through the focal point.
Question
A beam of white light is incident on a triangular glass prism with an index of refraction of about 1.5 for visible light, producing a spectrum. Initially, the prism is in a glass aquarium filled with air, as shown above. If the aquarium is filled with water with an index of refraction of 1.3, which of the following is true?
(A) A spectrum is produced, but the deviation of the beam is opposite to that in air.
(B) The positions of red and violet are reversed in the spectrum.
(C) The spectrum produced has greater separation between red and violet than that produced in air.
(D) The spectrum produced has less separation between red and violet than that produced in air.
Answer/Explanation
Ans: D
Solution: The larger the difference between n’s the more the rays bend. When the water is added, the difference between n’s is less so the amount of bending is less.
Questions:
A light ray R in medium I strikes a sphere of medium II with angle of incidence θ, as shown above. The figure shows five possible subsequent paths for the light ray.
Question(a)
Which path is possible if medium I is air and medium II is glass?
(A) path A (B) path C (C) path D (D) path E
Answer/Explanation
Ans: D
Solution: Medium I (air) is surrounding the sphere on both sides. As it enters the sphere, it goes less–more so bends towards the normal line (leaving D or E as the possibly answers). When the ray reaches the far edge of the sphere, it goes from more–less so should bend away from the normal line. Note the normal line drawn below.
Question
Multiple Correct: As shown, a beam of white light is separated into separate colors when it passes through a glass prism. Red light is refracted through a smaller angle than violet light
because red light has a: Select two answers.
(A) slower speed in glass than violet light
(B) faster speed in glass than violet light
(C) slower speed in the incident beam than violet light
(D) lower index of refraction in glass than violet light
Answer/Explanation
Ans: B,D
Solution: Bending of a wave (refraction) is due to the speed change at an angle. The more the speed changes, the more the bending. Hence, the violet bends more so must have a larger speed change (more slowing), so the red is faster. Additionally, we can note that since the violet slows and bends more, the index of refraction in glass for a violet light is higher than the index for a red
light.