Mirror Formula Calculations

Calculate the focal length of a mirror if the object distance is 20 cm and the image distance is 30 cm.

• 60 cm

• 40 cm

• 70 cm

• 50 cm

An object is placed 15 cm in front of a concave mirror. If the focal length is 10 cm, calculate the image distance.

• -30 cm

• 5 cm

• 40 cm

• -20 cm

If the object distance is 40 cm and the image distance is 20 cm, calculate the focal length of the mirror.

• 13.33 cm

• 25 cm

• 10 cm

• 15 cm

A concave mirror forms a real image 24 cm in front of the mirror when the object is placed 12 cm in front of it. Calculate the magnification.

• -2

• 0.5

• 1

• 3

An object is placed 30 cm in front of a convex mirror. If the image distance is 10 cm, calculate the magnification.

• 0.5

• 1/3

• -1/3

• 3

Calculate the object distance if the image distance is 15 cm and the magnification is -2 for a concave mirror.

• 30 cm

• 7.5 cm

• 0 cm

• -7.5 cm

If the object distance is 25 cm and the magnification is -1.5, calculate the image distance for a convex mirror.

• 25 cm

• 42.5 cm

• -37.5 cm

• 37.5 cm

A concave mirror forms a real image 18 cm in front of the mirror when the object is placed 9 cm in front of it. Calculate the magnification.

• 0.5

• 1

• -2

• 3

An object is placed 20 cm in front of a concave mirror. If the focal length is 15 cm, calculate the image distance.

• 10 cm

• -30 cm

• 25 cm

• -60 cm

If the object distance is 50 cm and the image distance is 25 cm, calculate the focal length of the mirror.

• 16.67 cm

• 30 cm

• 12.5 cm

• 20 cm