An engraver uses a magnifying glass (f=9.5 cm) to examine some work. (a) How far from the lens should you hold the print to see a final virtual image 30 cm from the lens (at the eye’s near point)? Conversion factor is the near point distance of the eye, which is estimated as 25 cm. Magnifying glass: The angular magnification of a magnifying glass depends on how the glass and the object are held, relative to the eye. A) what is the distance between the work and the magnifying glass? Physics University Physics Volume 3 Find the angular magnification of an image by a magnifying glass of f = 5.0 cm if the object is placed d o = 4.0 cm from the lens and the lens is close to the eye. The image he sees is located 25 cm from his eye, which is his near point. Homework Equations M= (1/f -1/di)N 1/di + 1/do = 1/f The Attempt at a Solution … Compared to the naked eye, a magnifying glass’ maximum angular magnification depends on how the object and the glass are held in relation to your eye. The magnification of a magnifying glass depends upon where it is placed between the user's eye and the object being viewed, and the total distance between them. Magnification M: Focal length f (cm): M = 25 cm / f Calculation of focal length and magnification of a magnifying glass. Reading with a magnifying glass You examine the fine print in a legal contract with a magnifying glass of focal length 5.0 cm. The angular magnification of a magnifying glass is therefore defined as \[\dfrac{\text{angular size of the image (which is}\space h/f )}{\text{angular size of the object when the object is at the near point (which is}\space h/D )}\] Hence the magnification is equal to \(D/f\). Magnifying Glass. Find the angular magnification of an image by a magnifying glass of f = 5.0 cm if the object is placed d o = 4.0 cm from the lens and the lens is close to the eye. b) what is the angular magnification of the magnifying glass? The magnification of a magnifying glass depends upon where it is placed between the user's eye and the object being viewed, and the total distance between them. The near point is taken to be 25 cm, so that a lens of focal length 2.5 cm has an angular magnification of 10. If the lens is held close to the eye such that its front focal point is on the object being viewed, the relaxed eye (focused on infinity) can view the image with angular magnification . The more the glass is curved, the smaller is the focal length, the stronger is the magnification of the glass. (b) Determine the angular magnification of the magnifying glass. Angular magnification and magnifying glasses. The Magnification Equation for a Magnifying Glass. The magnifying power is equivalent to angular magnification (this should not be confused with optical power, which is a different quantity). m.A = 25 cm/f .