Lens Formula and Image Formation

What is the lens formula used to calculate the position of an image?

• (1/f = 1/v + 1/u)

• (1/f = 1/v - 1/u)

• (1/f = 2/v + 2/u)

• (1/f = 1/v^2 + 1/u^2)

If an object is placed 50cm from a converging lens of focal length 10cm, where is the image formed?

• 12.5cm on the same side of the lens as the object

• 12.5cm on the opposite side of the lens to the object

• 25cm on the same side of the lens as the object

• 25cm on the opposite side of the lens to the object

What is the magnification (M) of an image if the object distance (u) is 50cm and the image distance (v) is 12.5cm?

• 0.25

• 4

• -0.25

• -4

For an object of height 1.6cm, what would be the height of the image formed if the magnification is 0.25?

• 0.4cm

• 0.8cm

• 6.4cm

• 4cm

When using the lens formula (1/f = 1/u + 1/v), if an object is placed 20cm from a converging lens of focal length 40cm, what is the image distance v?

• -40cm

• 40cm

• 20cm

• -20cm

If an image is formed on the same side of the lens as the object, what type of image is it?

• Real and inverted

• Real and upright

• Virtual and inverted

• Virtual and upright

For an object placed at a distance u from a lens, if the magnification (M) is given by (M = -v/u) and the image distance (v) is -40cm with u being 20cm, what is the magnification?

• 2

• -2

• 0.5

• -0.5

What is the diameter of the image if a 2.2cm diameter object is magnified by a factor of -2?

• 1.1cm

• 2.2cm

• 4.4cm

• 8.8cm

If the magnification (M) of an image is 1.5 and the object height is 1.6m, what is the height of the image?

• 0.8m

• 1.6m

• 2.4m

• 3.2m

Using the power formula (P = 1/f), where f is in meters, if the focal length of a lens is 2m, what is the power of the lens in diopters?

• 0.5D

• 1D

• 2D

• 0.83D