# Worksheet: The Simple Magnifier

Q1:

You view a mountain with a magnifying glass of focal length cm. What is the magnification?

• A3.4x
• B2.9x
• C3.7x
• D2.5x
• E4.0x

Q2:

A magnifying glass produces an angular magnification of 4.5x when used by a person with a near point of 18 cm. What is the maximum angular magnification obtained with the lens by a person with a near point of 45 cm?

• A8.8x
• B8.5x
• C9.3x
• D9.8x
• E9.5x

Q3:

How far should you hold a 2.1-cm-focal length magnifying glass from an object to obtain a magnification of 10x? Assume you place your eye 5.0 cm from the magnifying glass.

Q4:

An object viewed with the naked eye subtends a angle. If you view the object through a 10x magnifying glass, what angle is subtended by the image formed on your retina?

Q5:

What will be the angular magnification of a convex lens with the focal length 2.5 cm?

• A13x
• B10x
• C15x
• D11x
• E16x

Q6:

A doctor examines a mole with a 10.0 cm focal length magnifying glass, which is held 12 cm from the mole. What magnification does the lens produce?

Q7:

A magnifying glass forms an image 10 cm on the opposite side of the lens from the object, which is 10 cm away. What is the magnification of this lens for a person with a normal near point if their eye 12 cm from the object? The lens-to-retina distance is 2.00 cm.

• A x
• B x
• C x
• D x
• E x

Q8:

A magnifying lens with a focal length of 14.0 cm is held 4.00 cm from an eye and the object is 13.0 cm from the eye. What is the magnification of the lens?

• A 9.25x
• B 12.3x
• C 8.33x
• D 10.7x
• E 7.00x

Q9:

While outdoors on a sunny day, a student holds a large convex lens of radius 5.0 cm vertically above a sheet of paper, producing a bright spot of light on the paper 2.0 cm in radius. The magnitude of the electric field within the bright spot of light is and that of the sunlight leaving the side of the lens facing the paper is . Find the ratio of to .

Q10:

Find the angular magnification of an image by a magnifying glass of = 6.3 cm if the object is placed = 5.8 cm from the lens and the lens is close to the eye.

Q11:

A magnifying glass produces a magnification of 4.00 when held at a distance of 6.00 cm from a coin. What is the focal length of the magnifying glass?

Q12:

What is the angular magnifier of a binocular that has a focal length of 1.9 cm for the eyepiece and a focal length of 9.0 cm for the objective?

Q13:

If the image formed on the retina subtends an angle of and the object subtends an angle of , what is the magnification of the image?

• A
• B
• C
• D
• E

Q14:

You view an object by holding a 3.50 cm focal length magnifying glass 10.0 cm away from it. How far from your eye should you hold the magnifying glass to obtain a magnification of 10.0x?