Calculate Focal Length

An object is located 35.0 cm from a converging lens. The lens forms a real image at a distance of 15.0 cm. What is the focal length?

• 0.0953 cm

• 10.5 cm

• 26.2 cm

• 0.0678 cm

An object is placed 20 cm from a concave mirror, and the image is formed 10 cm from the mirror. Calculate the focal length of the mirror.

• 5 cm

• 6.67 cm

• 7.5 cm

• 10 cm

A lens has a focal length of 25 cm. If an object is placed 50 cm from the lens, where will the image be formed?

• 16.67 cm

• 25 cm

• 33.33 cm

• 50 cm

A convex lens forms a virtual image at a distance of 30 cm from the lens. If the object is placed 10 cm from the lens, what is the focal length?

• 7.5 cm

• 15 cm

• 20 cm

• 25 cm

An object is placed 40 cm from a convex lens, and the image is formed 80 cm on the other side of the lens. Calculate the focal length of the lens.

• 13.33 cm

• 20 cm

• 26.67 cm

• 40 cm

A concave lens has a focal length of 15 cm. If an object is placed 30 cm from the lens, where will the image be formed?

• -10 cm

• -15 cm

• -20 cm

• -30 cm

A lens has a focal length of 10 cm. An object is placed 15 cm from the lens. Calculate the image distance.

• 6 cm

• 10 cm

• 30 cm

• -30 cm

An object is placed 25 cm from a concave mirror, and the image is formed 50 cm from the mirror. What is the focal length of the mirror?

• 8.33 cm

• 12.5 cm

• 16.67 cm

• 25 cm

A convex lens has a focal length of 20 cm. If an object is placed 60 cm from the lens, where will the image be formed?

• 15 cm

• 20 cm

• 30 cm

• 40 cm

An object is placed 10 cm from a concave lens, and the image is formed 5 cm from the lens. Calculate the focal length of the lens.

• -3.33 cm

• -5 cm

• -6.67 cm

• -10 cm