Chapter 23 Mirrors and Lenses CHAPTER 23 Conceptual Questions C1 An eyeglass lens is cut with one surface having a radius R 1 and the other surface having a radius R2 with R1 R2 Both positive radii are measured from the same side with R 1 being the side closer to the eye Is this convex concave lens a converging lens or a diverging lens a This is a converging lens b This is a diverging lens c This can be either a converging or diverging lens as more information is needed for a final determination d This is neither since a lens cannot be made this way C2 A concave mirror has radius R When an object is located a distance 2R from the lens which describes the image formed a real inverted diminished b real inverted enlarged c virtual upright diminished d real inverted of equal size C3 A convex lens has a focal length of magnitude F At which of the following distances from this lens would a real object give an inverted virtual image a F b 2F c Any value greater than 2F d This cannot be done with a convex lens C4 A real object is place a distance d from a converging lens The object is then moved to a distance 2d from the converging lens Which of the following statements is false a The image in the first case with the object at distance d can be the larger one b The image in the second case with the object at distance 2d can be the larger one c If both images are real the image in the second case is smaller d If the image in the first case is real the image in the second case is upright C5 A real object is place to the left of a converging lens and an image forms Then to the right of the converging lens a diverging lens is placed A real inverted final image forms to the right of the diverging lens Which of the following could give this result a An upright virtual image caused by the first lens forms between the two lenses b An inverted real image caused by the first lens forms between the two lenses 139 Chapter 23 Mirrors and Lenses c A real upright image was formed by the first lens to the right of where the diverging lens is to be placed d A real inverted image was formed by the first lens to the right of where the diverging lens is to be placed 23 1 Flat Mirrors 1 You stand two feet away from a plane mirror How far is it from you to your image a 2 0 ft b 3 0 ft c 4 0 ft d 5 0 ft 2 Which of the following best describes the image from a plane mirror a virtual and magnification greater than one b real and magnification less than one c virtual and magnification equal to one d real and magnification equal to one 3 When the reflection of an object is seen in a plane mirror the image is a real and upright b real and inverted c virtual and upright d virtual and inverted 4 When the reflection of an object is seen in a plane mirror the distance from the mirror to the image depends on a the wavelength of light used for viewing b the distance from the object to the mirror c the distance of both the observer and the object to the mirror d the size of the object 5 If a man wishes to use a plane mirror on a wall to view both his head and his feet as he stands in front of the mirror the required length of the mirror a is equal to the height of the man b is equal to one half the height of the man c depends on the distance the man stands from the mirror d depends on both the height of the man and the distance from the man to the mirror 140 Chapter 23 Mirrors and Lenses 6 The lateral magnification for a flat mirror a is a function of the object distance b is a function of the image distance c is a function of the object and image distance d is 1 141 Chapter 23 Mirrors and Lenses 7 How large should a wall mounted mirror be to view the upper half of one s height h a h b h 2 c h 4 d The answer is not given 23 2 Images Formed by Concave Mirrors 23 3 Convex Mirrors and Sign Conventions 8 The real image of an object is located 45 0 cm away from a concave mirror which has a focal length of 10 0 cm How far is the object from the mirror a 40 0 cm b 35 0 cm c 22 5 cm d 12 9 cm 9 A concave mirror forms a real image at 25 0 cm from the mirror surface along the principal axis If the corresponding object is at a 10 0 cm distance what is the mirror s focal length a 1 43 cm b 16 7 cm c 12 4 cm d 7 14 cm 10 If a virtual image is formed along the principal axis 10 cm from a concave mirror with the focal length 15 cm what is the object distance from the mirror a 30 cm b 10 cm c 12 cm d 6 0 cm 11 If a virtual image is formed 10 0 cm along the principal axis from a convex mirror of focal length 15 0 cm how far is the object from the mirror a 30 0 cm b 10 0 cm c 6 00 cm 142 Chapter 23 Mirrors and Lenses d 3 00 cm 143 Chapter 23 Mirrors and Lenses 12 A woman looking in a makeup mirror sees her face at twice its actual size and right side up If she is 28 0 cm from the mirror what is its focal length a 18 6 cm b 44 0 cm c 48 3 cm d 56 0 cm 13 Which best describes the image of a concave mirror when the object is located somewhere between the focal point and twice the focal point distance from the mirror a virtual upright and magnification greater than one b real inverted and magnification less than one c virtual upright and magnification less than one d real inverted and magnification greater than one 14 Which of the following best describes the image of a concave mirror when the object is at a distance greater than twice the focal point distance from the mirror a virtual upright and magnification greater than one b real inverted and magnification less than one c virtual upright and magnification less than one d real inverted and magnification greater than one 15 Which of the following best describes the image of a concave mirror when the object s distance from the mirror is less than the focal point distance a virtual upright and magnification greater than one b …